where is the inertia switch supposed to be

[robvanderveer]

mine was already removed before i bought it, i can see no holes in the footwell behind the carpet. No one the left side, not on the back.

perhaps somebody has a picture clearly showing the spot?

[Domi]

I think this might help you:
http://2.bp.blogspot.com/-HBNXQsRP2_Q/UOzY2UTkHXI/AAAAAAAADYk/ZcykNThYHgs/s1600/IMG_4475.JPG

[robvanderveer]

Right! thanks! (yeah, left)

That would mean i'd have to extend the wires because FPO (f...ing prev owner) decided just to cut the wires 10 cm from the plug. Hurray.

[David T]

I think this might help you:
http://2.bp.blogspot.com/-HBNXQsRP2_Q/UOzY2UTkHXI/AAAAAAAADYk/ZcykNThYHgs/s1600/IMG_4475.JPG

Originally the switch was on a bracket on the Lambda counter (that white box you see in the center of the picture) but it was getting kicked so it was moved to the left side of the footwell. There was also a recall on the early switches. If you have a switch but it doesn't have a splotch of white paint on it you should replace it. Refer to SC-06-7/82. Be careful cutting and splicing the wiring. There are 2 separate circuits. One is the ground for the fuel pump and one is to unlock the doors. Do NOT mix them up.

[robvanderveer]

Yes David, i know. My switch has no white spot because i bought it two years back at DMCEu, because my car had no switch at all. My VIN is 3695 (sept '81) so that probably before that recall (’82), and the bracket is missing.

[Chris4099]

Here's all the info you need about mounting the switch in the proper location:
http://www.dmcnews.com/bulletins/SC-06-7.82.html

I've performed this modification several times with no issues using the included paper template. I highly recommend people with an original switch without the white dot get it replaced. I didn't know about this recall until my original one decided to not let my car start one morning! Thankfully it happened while I was at home instead of while driving.

[robvanderveer]

that template is useful, thanks for the link.

[Jonathan]

Ok, in the "learn a new thing every day" category, I gotta ask...

David mentioned the inertia switch getting kicked. I thought the switch got moved because people figured out how to get in your car by banging the panel from the outside and getting your doors to unlock? Are you saying the banging of the switch is actually related to the driver hitting it themselves by accident?

I had never thought of it that way. I have the electrical portion of my door locks disconnected so had never paid it much attention. The killing of the fuel pump though is still kind of important.

[robvanderveer]

as far as I know, the doors will only unlock when the key is in accessory mode?

and as a side note, i guess you'd have to kick the car pretty hard...

[Chris4099]

as far as I know, the doors will only unlock when the key is in accessory mode?


I'm not sure on the other questions, but I can say that if you manage to trigger the inertia switch, it will unlock the doors, regardless of the key position. When connected and working properly, the power door locks will work at anytime. Since the inertia switch triggers the lock by grounding the trigger wire, this will work regardless if the engine is on or not.

[DMCMW Dave]

The QAC "pogs" have often mentioned getting into locked cars on the lot with a sharp blow to the rear of the left front fender with a rubber mallet.

There as suspicions that is why the switch was moved rather than for some nebulous safety reason.

[sdg3205]

I have yet to see an original non-white blotch inertia switch that hasn't melted down. Josh - if you're reading this are you still running yours?

Has anyone ever actually kicked their bracket mounted switch and tripped it?

[NightFlyer]

I have yet to see an original non-white blotch inertia switch that hasn't melted down. Josh - if you're reading this are you still running yours?

Has anyone ever actually kicked their bracket mounted switch and tripped it?

Never had a reason to check my inertia switch, thus I don't know if it has the white blotch or not - I'll take a look-see tomorrow.

[robvanderveer]

good info guys, thanks. I'd like to know before drilling the tub.

[Farrar]

Interesting ... #2613's inertia switch is mounted next to the lambda box, not on the adjacent panel as shown in the linked photo. Even though the switch is so close to the pedals, I've never tripped it by accident.

[DMCMW Dave]

Interesting ... #2613's inertia switch is mounted next to the lambda box, not on the adjacent panel as shown in the linked photo. Even though the switch is so close to the pedals, I've never tripped it by accident.

http://www.dmcnews.com/bulletins/SC-06-7.82.html

[robvanderveer]

http://www.dmcnews.com/bulletins/SC-06-7.82.html



http://www.dmcnews.com/bulletins/SC-06-7.82.html
Thanks, but we already got that one.

[DMCMW Dave]

Thanks, but we already got that one.

Yeah - I noticed that too late to edit.

[robvanderveer]

no worries mate, better two than none.

[jawn101]

I have yet to see an original non-white blotch inertia switch that hasn't melted down. Josh - if you're reading this are you still running yours?

Has anyone ever actually kicked their bracket mounted switch and tripped it?

I was on a club drive with Clint (vwdmc16) and he did exactly this - but he's about 10 feet tall, at least 8' of which is his legs. We were going up a hill and he suddenly seemed to be going really slow... at the next stop he revealed he had kicked the switch by accident and cut the engine off.

[Farrar]

The QAC "pogs" have often mentioned getting into locked cars on the lot with a sharp blow to the rear of the left front fender with a rubber mallet.

Ah HA! Now we know the REAL reason why there are so few left front fenders! LOL

[DMCMW Dave]

Ah HA! Now we know the REAL reason why there are so few left front fenders! LOL

I was thinking the same thing.

[NightFlyer]

I have yet to see an original non-white blotch inertia switch that hasn't melted down. Josh - if you're reading this are you still running yours?

Has anyone ever actually kicked their bracket mounted switch and tripped it?

OK, sorry it took me a while, but where exactly would the white blotch be located? I don't see anything white on the housing of my switch.

Here's a picture of mine, which hasn't given me any kind issues that I'm aware of.

To be honest, I never really gave the thing much thought....

http://dmctalk.org/attachment.php?attachmentid=22938&d=1383901938

[sdg3205]

The white spot is like a blotch of white paint or white out on the drivers side or passenger side (against the mounting bracket) of the switch.

Whatever you're doing to keep your car running flawlessly on all the dunmurry parts and fluids, keep it up!

[NightFlyer]

The white spot is like a blotch of white paint or white out on the drivers side or passenger side (against the mounting bracket) of the switch.

Whatever you're doing to keep your car running flawlessly on all the dunmurry parts and fluids, keep it up!

Yeah, no white blotch anywhere on the thing.

It's my 'special magic' :wink:

Any idea what the green dot on the lambda counter indicates, if anything? It definitely looks like an intentional marking to me...

[BABIS]

I guess your switch does not have the white dot because it has not been relocated as per the service bulletin..

[robvanderveer]

Just let me ask you to be sure: I assume the recall was done for the quality of the switch, no so much for the location of the switch?

What i'm wanting to know, i have a brand new inertia switch, can I simply (re)mount it to the bracket?

[Bitsyncmaster]

This is an interesting discussion on the inertia switch. I was wondering what G force and in what directions would cause the switch to trip. Other cars use an inertia switch to fire the air bags but it's not discussed if those switches are a one time trip (need replacement) or if they reset themselves. I would guess the switch will not trip if you lockup your brakes.

This interest came about since I'm thinking of using that switch to do an automatic battery cutoff relay. Then I would not need to run fuel pump power through the switch.

[BABIS]

Just let me ask you to be sure: I assume the recall was done for the quality of the switch, no so much for the location of the switch?

What i'm wanting to know, i have a brand new inertia switch, can I simply (re)mount it to the bracket?

take a look here : http://dmcnews.com/bulletins/SC-06-7.82.html

[robvanderveer]

take a look here : http://dmcnews.com/bulletins/SC-06-7.82.html

Ok, Babis, that link has been posted 5 times now.

[robvanderveer]

This is an interesting discussion on the inertia switch. I was wondering what G force and in what directions would cause the switch to trip. Other cars use an inertia switch to fire the air bags but it's not discussed if those switches are a one time trip (need replacement) or if they reset themselves. I would guess the switch will not trip if you lockup your brakes.

This interest came about since I'm thinking of using that switch to do an automatic battery cutoff relay. Then I would not need to run fuel pump power through the switch.

I assume you are planning to use the switch to drive a relay. Now i don't know the absolute maximum ratings of the inertia switch, but i'm sure it is designed to do what it is supposed to do: cut of the fuel pump. I'd rather have one device that can possibly fail, than 2 devices that can possibly fail. And if your fiel pump is pulling too much current, my guess would be to solve that instead of adding more components to mask a design fault.

[BABIS]

Ok, Babis, that link has been posted 5 times now.

Just to be sure :rock_on:

[Bitsyncmaster]

I assume you are planning to use the switch to drive a relay. Now i don't know the absolute maximum ratings of the inertia switch, but i'm sure it is designed to do what it is supposed to do: cut of the fuel pump. I'd rather have one device that can possibly fail, than 2 devices that can possibly fail. And if your fiel pump is pulling too much current, my guess would be to solve that instead of adding more components to mask a design fault.

I was planing an emergency battery cut off with a latching relay anyway. It was just an afterthought to have the inertia switch trigger that cut off after one second (so the doors unlock). Then the fuel pump would be cut off anyway (since battery power is off) so why not remove the voltage drops on the fuel pump of the ground side wires, connectors (near the washer pump) and switch itself.

Emergency battery cutoff is mostly for wire shorts that are not fused. Most of that wiring is in the passenger side rear end of the car. So in the event of an accident there is my stop a fire.

[NightFlyer]

I would guess the switch will not trip if you lockup your brakes.

I can personally confirm that my switch did NOT trip when I momentarily locked up my brakes en route to DCS :biggrin:

[robvanderveer]

If you do the math, it is very unlikely that you trip the inertia switch with just braking. Typical values are around 10G's peak to trip the switch, while heavy braking on modern production cars may be no more than 2.2-2.8g. Formula 1 cars can pull about 5g on breaking. Compare that to hitting a wall. Now i do think that hitting a pothole of some sort could trigger the switch, but if that happens i'd advise you to review your shock absorbers.

[Chris4099]

To be honest, I never really gave the thing much thought....

I didn't give much thought to my pre-recall switch as well until one morning when my car wouldn't start because of it! I was pretty lucky it didn't fail while driving.

Considering how little time it was between the start of production and that recall, it must have been pretty obvious to DMC at the time that the switch was defective and failure prone. That's why I give the DMC recalls a high priority on the "to-do" list. If they knew of a problem with such short time, you know it had to be a major issue!

[robvanderveer]

Do not be mistaken! I totally agree with the recall. The inertia switch should not trip BY accident, only IN an accident (english is touch here, note the difference).

[NightFlyer]

I didn't give much thought to my pre-recall switch as well until one morning when my car wouldn't start because of it! I was pretty lucky it didn't fail while driving.

Considering how little time it was between the start of production and that recall, it must have been pretty obvious to DMC at the time that the switch was defective and failure prone. That's why I give the DMC recalls a high priority on the "to-do" list. If they knew of a problem with such short time, you know it had to be a major issue!

If mine ever fails, I'll just jumper it :thumbup:

[Chris4099]

That's what I did too until my replacement arrived. Still sucked having to spend time figuring why my car didn't start in the first place (no melting or other obvious sign it was the problem). Since it's one of those "not if, but when" failures, others should just do it now and then not have to worry about again for the foreseeable life of the car.

[NightFlyer]

That's what I did too until my replacement arrived. Still sucked having to spend time figuring why my car didn't start in the first place (no melting or other obvious sign it was the problem). Since it's one of those "not if, but when" failures, others should just do it now and then not have to worry about again for the foreseeable life of the car.

I'm not very pro-active with my car :wink:

But for others, it very well may be a good thing to be pro-active with :thumbup:

[Jonathan]

Originally the switch was on a bracket on the Lambda counter (that white box you see in the center of the picture) but it was getting kicked so it was moved to the left side of the footwell. There was also a recall on the early switches. If you have a switch but it doesn't have a splotch of white paint on it you should replace it. Refer to SC-06-7/82. Be careful cutting and splicing the wiring. There are 2 separate circuits. One is the ground for the fuel pump and one is to unlock the doors. Do NOT mix them up.


I didn't give much thought to my pre-recall switch as well until one morning when my car wouldn't start because of it! I was pretty lucky it didn't fail while driving.

Considering how little time it was between the start of production and that recall, it must have been pretty obvious to DMC at the time that the switch was defective and failure prone. That's why I give the DMC recalls a high priority on the "to-do" list. If they knew of a problem with such short time, you know it had to be a major issue!

I was looking at this thread closer and had a couple comments about the timing or sequence of things.

The date on the recall is July 1982, so this isn't very near the beginning of production, closer to the end rather. I know it was also released earlier as a recall, but initially focusing on moving the switch, but not replacing it.

The reason I mention it is related to the "fail when and not if" thought.


That's what I did too until my replacement arrived. Still sucked having to spend time figuring why my car didn't start in the first place (no melting or other obvious sign it was the problem). Since it's one of those "not if, but when" failures, others should just do it now and then not have to worry about again for the foreseeable life of the car.

It sounds to me like the first recall was intended on moving the switch because it was getting kicked or bumper or had something to do with people getting into your car by whacking the wheel well or fender area.

Then along came the July 1982 recall and it was about replacing the switch as well as relocating it if not done already. Part way through the document it mentions doing only the replacement and it not taking as long or requiring as many parts.

So to me it says there were two different issues going on here.

It explains the two ways it can fail, either open and cutting off the fuel pump, or closed and keeping the fuel pump running. This sounds like the only way a switch doing only two things can fail to me. How could it fail in between for example? What it doesn't say is why it fails. Yes, there is concern for either failure mode, but no explanation is given as to why it fails (bad internals, poor solder joints, overheating, etc., etc.)

The piece about when and not if seems skeptical as none of us know the context of this decision. Listening to old stories from Dunmurry or the QAC's and it seems there were a ton of things done or decided upon for very od reasons. The front suspension recall on the 3rd car out the door getting driven into a curb, the gas flap hood getting changed because one grouchy guy (CR Brown) didn't want to deal with the cost or hassle of them, changing stereo suppliers from Craig to ASI not because of the radio but because one had a clock and one didn't and the console clocks were crap, etc., etc.

We can all do the better safe than sorry stuff, but there is a limit and a line somewhere that makes some of it unnecessary. Josh pointed out running on his very original car with the same one it always came with and not fearing a failure. It's been mentioned elsewhere and I feel the biggest reason any of us can do such things is because of being familiar with our cars. If you don't know your car well or what to do or think when something goes wrong, then you can't approach it this way.


Yeah, no white blotch anywhere on the thing.

It's my 'special magic' :wink:

Any idea what the green dot on the lambda counter indicates, if anything? It definitely looks like an intentional marking to me...

I have the same greenish spots as you do and also no white splotch on the switch. I don't know what the marks on the lambda counter mean either.

28775

[Chris4099]

I was looking at this thread closer and had a couple comments about the timing or sequence of things.

The date on the recall is July 1982, so this isn't very near the beginning of production, closer to the end rather. I know it was also released earlier as a recall, but initially focusing on moving the switch, but not replacing it.

The reason I mention it is related to the "fail when and not if" thought.

I worded that poorly. I was thinking in the life of the car (all 33 years), considering what we've learned just through the passage of time, for something to be noticed so early on, it's probably a frequent issue. So for any DMC recall, it must have been pretty big deal for them to have one within their short period of production.



The piece about when and not if seems skeptical as none of us know the context of this decision. Listening to old stories from Dunmurry or the QAC's and it seems there were a ton of things done or decided upon for very od reasons.

All I can say is I'm somebody that's had them fail in the open position resulting in a car that won't drive, it's a good enough reason to replace them. I never broke the failed one apart to figure out the exact cause, but I'm sure when DMC was investigating what had to have been a high failure rate of these, they figured out the cause and the new part has that issue addressed. Speculation on my part, but consistent with how companies work when it comes to safety devices.



We can all do the better safe than sorry stuff, but there is a limit and a line somewhere that makes some of it unnecessary. Josh pointed out running on his very original car with the same one it always came with and not fearing a failure. It's been mentioned elsewhere and I feel the biggest reason any of us can do such things is because of being familiar with our cars. If you don't know your car well or what to do or think when something goes wrong, then you can't approach it this way.

Josh may not have a fear of failure, but that doesn't actually change the odds of failure. I had no fear of mine failing or even gave the recall any though until it failed. I get where you say you can take things too far, but for me performing factory recalls is not going too far. Automotive companies don't take recalls lightly and normally resist issuing them (plenty of examples in the past of this happening), so when they do actually issue one, I take it seriously now.

A more glamorous example are all the threads in the past of suspension failures from people who don't install the castle nuts per that other recall.

[Jonathan]

Hey Chris, you know, just in the last part of your message it made a ton of sense to me. When you mentioned it being a "factory recall."

Not all the business about how or why it fails or the context or what not, but the part where I was mentioning the "taking it too far" part. I had forgotten for a minute that this was actually a recall and unlike the other examples I had in my mind, it isn't all just urban legends (you would assume).

TABs come to mind immediately. Not saying they can't fail or that they are worthwhile to check on or replace, but the fear factor stories that accompany it sometimes stretch things further or worse than they really are.

Another one I have a recent personal experience with is the orange Grady hoses at your fuel pump going a short distance to the hard lines. I can see how these may be deteriorating on many cars at a certain age, but when I replaced mine they were not broken down inside at all after cutting them open. This isn't that bad on it's own except what came a month or two after the work was done. I had replaced them when my workspace was a bit cold still and the hoses weren't very soft or malleable at the time. Fast forward to DCS weekend and on the way home one of the hoses came loose. After getting it figured out (on the side of the highway mind you), I could see and feel that the hoses got much more workable or soft after getting warm. It simply boiled down to not tightening the clamp enough and doing it against a stiff hose only made it more so. The story ended ok, but I got thinking maybe I would have been better off leaving them alone.

So, yea, my thoughts might have been better explained as "if it ain't broke don't fix it." And like you pointed out, we can keep that in mind for many things on the car just perhaps not on the recall items. Thanks for explaining it for me.

[David T]

I worded that poorly. I was thinking in the life of the car (all 33 years), considering what we've learned just through the passage of time, for something to be noticed so early on, it's probably a frequent issue. So for any DMC recall, it must have been pretty big deal for them to have one within their short period of production.



All I can say is I'm somebody that's had them fail in the open position resulting in a car that won't drive, it's a good enough reason to replace them. I never broke the failed one apart to figure out the exact cause, but I'm sure when DMC was investigating what had to have been a high failure rate of these, they figured out the cause and the new part has that issue addressed. Speculation on my part, but consistent with how companies work when it comes to safety devices.



Josh may not have a fear of failure, but that doesn't actually change the odds of failure. I had no fear of mine failing or even gave the recall any though until it failed. I get where you say you can take things too far, but for me performing factory recalls is not going too far. Automotive companies don't take recalls lightly and normally resist issuing them (plenty of examples in the past of this happening), so when they do actually issue one, I take it seriously now.

A more glamorous example are all the threads in the past of suspension failures from people who don't install the castle nuts per that other recall.

There is another thing to keep in mind about the inertia switch. Some owners use it as a "kill" switch so the car won't run. They reach in and lift the plunger which prevents the fuel pump from running so the car is harder to steal. IMHO this is not a good idea since this switch was never meant to be cycled in this manner and can wear out quickly. A better deterrent would be a battery master switch.

[NightFlyer]

Has anyone actually cracked open an original and later switch to compare the two?

From the outside casing, they look virtually identical to me, thus I strongly suspect that they are in fact the same switch internally as well. This of course suggests that any defect in the original switch was either a manufacturing defect or resultant of improper installation (including mounting location), as opposed to a design defect. Hard to say what the experienced failure rate on the original switches were, but I'm willing to bet that most were good when they were originally installed - after all, 33 years on mine and still working fine proves something, doesn't it?

It's my opinion that the failures that triggered the recall had to do with improper installation (mounting location), as opposed to the switches actually being defective.

What makes me believe this more than anything else is the fact that the recall on the switch was issued in conjunction with the mandated relocation of the switch. How many failures were caused by drivers who were frequently kicking the damn thing with wet/dirty shoes, due to the original mounting location's proximity to the pedal box? To me anyway, this strongly suggests improper installation as opposed to an actual defective product.

That's admittedly pure speculation. However, as we don't know the exact details behind the recall, there's nothing upon which to actually assert with any kind of accuracy that the original switches were defective - that's also nothing more than pure speculation.

Unless you can fully account for how the switch was treated under previous ownership of your car, just because you experienced the failure of the original switch on your car doesn't necessarily mean that the switch itself was defective - it very well may have experienced a rough life prior to your ownership that exceeded the original design specs/tolerances.

As to the front end recall, that's a similar story - it wasn't because of a defective design or improper parts selection, but was rather resultant of improper assembly/installation. Castle nuts aren't necessary - they're just more idiot proof and permit a greater degree of slop (which shouldn't be present in a proper installation) in the assembly.

Thus, I fully agree with Jonathan's original post.

One of the motto's I live by with my car is 'if it ain't broke, don't fix it.' The less you mess with shit that's working fine, the greater your chances are of having it continue to work fine into the future.

I also treat my car as if everything on it is somewhat delicate, as after all, it's 33 years old, thus why wouldn't you?

[Bitsyncmaster]

Here is a thought. The holes for the two mounting screws have an indent. I have not seen a photo of an original one mounted on the bracket but if it mounted on the left side and you moved it to the mount it on the foot well then those indents would be on the wrong side. If you flipped it that would make the plunger point to the front.

[David T]

Here is a thought. The holes for the two mounting screws have an indent. I have not seen a photo of an original one mounted on the bracket but if it mounted on the left side and you moved it to the mount it on the foot well then those indents would be on the wrong side. If you flipped it that would make the plunger point to the front.

There have been more than a few cases where the owner could not start the car and the trouble turned out to be the inertia switch and it didn't have the white paint on it. Once replaced the problem was solved. Position and orientation of the switch is critical or it won't trigger. There is a metal ball inside that rolls around and is what is affected by the G forces, causing the switch to trip.

[JohnZ]

What about asking mr. Nick Sutton about the inertia switch recall? He might know something more, isn't it?

:)

[SS Spoiler]

I think my switch has been jumpered from day one, 26 years.

[Chris4099]

Has anyone actually cracked open an original and later switch to compare the two?

From the outside casing, they look virtually identical to me, thus I strongly suspect that they are in fact the same switch internally as well. This of course suggests that any defect in the original switch was either a manufacturing defect or resultant of improper installation (including mounting location), as opposed to a design defect. Hard to say what the experienced failure rate on the original switches were, but I'm willing to bet that most were good when they were originally installed - after all, 33 years on mine and still working fine proves something, doesn't it?

It's my opinion that the failures that triggered the recall had to do with improper installation (mounting location), as opposed to the switches actually being defective.

Interesting that you put speculation and saving $56 over safety and reliability. I guess we are just different that way. :-) As for yours proving something, how many miles do you have on it again and how much has it been driven compared to the average D? Mine had 24K on it when my original failed 10 years ago. 25K miles have since been put on the replacement with no issues. My sample size of 1 says you are wrong. LOL


As to the front end recall, that's a similar story - it wasn't because of a defective design or improper parts selection, but was rather resultant of improper assembly/installation. Castle nuts aren't necessary - they're just more idiot proof and permit a greater degree of slop (which shouldn't be present in a proper installation) in the assembly.

Let me tell you a quick story... Several years ago, Bill R had his LCA detach from the sway bar. He replaced the nylock nut with another one and called it good (after another one of his rants on the engineering of the car). I then showed there was a recall on that very part and to use double nuts instead. He thought the new nylock and additional loctite was good enough. A Boeing employee then posted about how when properly torqued (which is indicated in the recall), double nutting is superior method of securing the fastener. I'm not sure if he finally switched, but I'll keep my sway bar and ball joints secured using the superior method over nylocks.


One of the motto's I live by with my car is 'if it ain't broke, don't fix it.' The less you mess with shit that's working fine, the greater your chances are of having it continue to work fine into the future.

I also treat my car as if everything on it is somewhat delicate, as after all, it's 33 years old, thus why wouldn't you?

I get what you are saying. There's been plenty of times where I've worked on something "just because" and it triggered a cascade of issues. But in the case of the recalls (in particular the inertia switch), we are talking about simple fixes that have a proven track record of being safer and more reliable with pretty much minimal risk.

[NightFlyer]

Interesting that you put speculation and saving $56 over safety and reliability. I guess we are just different that way. :-) As for yours proving something, how many miles do you have on it again and how much has it been driven compared to the average D? Mine had 24K on it when my original failed 10 years ago. 25K miles have since been put on the replacement with no issues. My sample size of 1 says you are wrong.

I fully conceded to my speculation. However, there's also nothing definitive proving that the original switches were defective - that's also little more than pure speculation, as I previously pointed out.

The FACT that the company mandated the relocation of the switch in conjunction with the replacement tells me that something other than just a defective part was going on here.

Just passed the 20k mark today. Guess we'll see how long mine lasts, but I fully expect it to be indefinitely. Time will tell :smile:

[Bitsyncmaster]

I fully conceded to my speculation. However, there's also nothing definitive proving that the original switches were defective - that's also little more than pure speculation, as I previously pointed out.

The FACT that the company mandated the relocation of the switch in conjunction with the replacement tells me that something other than just a defective part was going on here.

Just passed the 20k mark today. Guess we'll see how long mine lasts, but I fully expect it to be indefinitely. Time will tell :smile:

I'll show you mine if you show me yours.....The switch that is.:p

Mine has the white dot and I will be happy to take it apart and take photos. I'm curious anyway how it works.

[NightFlyer]

I'll show you mine if you show me yours.....The switch that is.:p

Mine has the white dot and I will be happy to take it apart and take photos. I'm curious anyway how it works.

Kinky - I like it, but it wasn't my switch that you wanted to see in Dayton :p

J/K :biggrin:

Ordinarily, I'd be more than happy to oblige, but as it's working, I'd prefer not to mess with it at all. Maybe Chris still has his old switch and would be game for a little comparative experimentation. You'd think that one of the vendors would have an old one lying around and wouldn't mind cracking it open.

[David T]

Kinky - I like it, but it wasn't my switch that you wanted to see in Dayton :p

J/K :biggrin:

Ordinarily, I'd be more than happy to oblige, but as it's working, I'd prefer not to mess with it at all. Maybe Chris still has his old switch and would be game for a little comparative experimentation. You'd think that one of the vendors would have an old one lying around and wouldn't mind cracking it open.

One reason for the recall may have been from testing they realized the inertia switches were not tripping at the specified force so in an accident they would not actuate. The fact that 20 years later we see them failing another way may be secondary to the recall. What we know for sure is if you don't have a switch with the paint on it, it is likely to fail and the fuel pump won't run leaving you stranded. You can be proactive and replace what you know will fail sooner rather than later or you can wait till failure and replace it then. Owner's choice.

[NightFlyer]

One reason for the recall may have been from testing they realized the inertia switches were not tripping at the specified force so in an accident they would not actuate. The fact that 20 years later we see them failing another way may be secondary to the recall. What we know for sure is if you don't have a switch with the paint on it, it is likely to fail and the fuel pump won't run leaving you stranded. You can be proactive and replace what you know will fail sooner rather than later or you can wait till failure and replace it then. Owner's choice.

How many actual documented failures you are aware of. Other than Chris' given example, and Dave G mentioning that he has seen a few, I'm not personally aware of any. A handful of experienced failures (probably less than 1% of those that are in existence) on a 33 year old part is hardly a reason to get all up in arms and proactive about it IMHO. Same can be said for plastic header bottle scare, TAB scare, etc....

[Chris4099]

I thought I still had my original failed unit (I still have a blue fan fail relay and metal case relays without the stripe), but it looks like it's gone. I probably tossed it thinking it was worthless. Dissecting it for debates on the Internet didn't occur to me back then. :-) I've swapped two others for local owners, but those too we tossed.

As for other failures, I recall several other threads in the old .com days talking about no-fuel issues being traced back to the inertia switch. The vendors could probably say how many failed pre-recall ones they replace.

[NightFlyer]

I thought I still had my original failed unit (I still have a blue fan fail relay and metal case relays without the stripe), but it looks like it's gone. I probably tossed it thinking it was worthless. Dissecting it for debates on the Internet didn't occur to me back then. :-) I've swapped two others for local owners, but those too we tossed.

As for other failures, I recall several other threads in the old .com days talking about no-fuel issues being traced back to the inertia switch. The vendors could probably say how many failed pre-recall ones they replace.

Thanks for checking :thumbup:

You'd probably freak out if I posted a picture of my relay/fuse compartment - it's mostly exactly as it came from Dunmurry :biggrin:

[sdg3205]

I took an OEM (non white dot) unit apart. Well, I tried... It just kinda exploded when I tried to pry it open.

The ones I have seen fail tend to melt at the male harness connection. This one had also melted up the side where an internal bracket/component poked out through the casing giving the look of buck-teeth.

Anyway I couldn't see why it failed, nor could I find all the bits and pieces after the explosion! Sorry guys.

[Bitsyncmaster]

I took an OEM (non white dot) unit apart. Well, I tried... It just kinda exploded when I tried to pry it open.

The ones I have seen fail tend to melt at the male harness connection. This one had also melted up the side where an internal bracket/component poked out through the casing giving the look of buck-teeth.

Anyway I couldn't see why it failed, nor could I find all the bits and pieces after the explosion! Sorry guys.

OK, I guess I won't open my working unit. I removed mine to look it over and my idea of the mounting indents is a bust. Indents on both sides. I found the company that made them but it may have been sold since they are now headquartered in the USA. The company logo symbol is what shows up on the case of my switch.

http://www.inertiaswitch.com/

There is a number " 0426K9 4 " marked on my switch with the white paint dot.

[Bitsyncmaster]

My guess is the switch has a spring loaded pendulum that will swing forward to open the contacts.

I also remember some old posts about melting caused by bad connections. It has to conduct the full fuel pump current to ground. Probably due to the connector pins on the unit.

[DMCMW Dave]

Same can be said for plastic header bottle scare, TAB scare, etc....

The problem with waiting for the header bottle to fail is that it can be catastrophic to the rest of the engine. Yes, so far the failure is rare (a few per year that we hear about) but if it cracks open at interstate speed, you have to be pretty observant to shut the engine off and coast to the side of the road before you overheat it enough to do damage (typically blown head gaskets). If it cracks open stuck in traffic, more likely actually due to the heat involved, it's just embarrassing and still means a tow.


Based on the history of your car, yours is probably OK for the time being assuming it's still somewhat milky white. We see them all the time that are dark brown with severe cracking. They will either fail at the center seam or the cracking at the rear will blow out. It is somewhat disingenuous to generalize that if yours is OK everyone else's is OK too without actually seeing them.

This is not strictly a DeLorean problem. Other cars (BMW, Audi for example) also use plastic pressure tanks, and they are commonly replaced at 100K miles (and are known for blowing up at about that, along with the plastic radiator tanks). 30-something years is pushing it.

[robvanderveer]

I say it is a very interesting discussion, but we're going a little off-topic here.

[jawn101]

Off topic maybe, but it's still very important to owner safety and the longevity of these cars that people understand fully what they are going in to with any of these known vulnerable parts. If someone consciously chooses to put themselves, their car and potentially others on the road at risk to prove a point (to themselves, to others, whatever - not concerned with motivation) then future readers of these threads should be made amply aware that this is exactly what is going on, and that they may wish to employ a different tactic themselves.

[NightFlyer]

Just for the record, I NEVER abdicated that just because the header bottle on my car was OK, that the same is true of everyone's car. In fact, I specifically state in my fully analysis/assessment of the header bottle situation that if an owner is unaware of the full history of their car, or if they ever personally encountered an overheating of the cooling system, that they'd be best to change out their bottles, as the stock/OEM ones don't allow much overhead (heat and/or pressure wise) in their design specs, and once pushed beyond those specs even once, you're potentially flirting with a disaster.

Cars stored/kept outdoors also have the disadvantage of being exposed to wild swings in temperature and humidity, as well as exposure to atmospheric impurities. And cars actually used in below freezing temperatures have the situation where the outside of the bottle is freezing when the car isn't being run, and exposure of the frozen bottle to the vibrations presented by usage in such temperatures definitely aren't ideal, as things get brittle when they're frozen (probably why you see the formation of cracks on the outside of the bottle before any indications of a problem appear inside the bottle). Cars that are staticly stored in freezing temperatures must also always be mindful of having the proper concentration of anti-freeze in the system/bottle.

The only situations in which I've ever asserted that it was OK to keep the plastic header bottle without much worry are ones in which the owner can affirmatively verify that 1) the cooling system was never operated in such a manner that exceeded the normal operating temperatures/pressures; 2) that when not being driven, the car was primarily stored/kept indoors; and 3) that if the car was ever kept in freezing environments, that it was rarely if ever used during such temperature spells AND that the proper concentration of anti-freeze was always maintained in the system/bottle. If an owner can positively confirm these three things, as I can with my car, then I personally don't see an issue with continuing to run the stock/OEM plastic header bottle.

This has always been my position in regards to that.

http://www.dmctoday.com/showthread.php?449-Alternative-to-the-DMC-coolant-bottle

[Farrar]

Just for the record, I NEVER abdicated

Is that "auto-correct" for "advocated"?

[NightFlyer]

Is that "auto-correct" for "advocated"?

No - that's simply a typed the wrong word and the time to edit had already expired by the time I realized it :biggrin:

[Timeless]

I have yet to see an original non-white blotch inertia switch that hasn't melted down. Josh - if you're reading this are you still running yours?

Has anyone ever actually kicked their bracket mounted switch and tripped it?
Old thread I know but while searching for inertia switch info I found this thread. My Nov. 81 car has an original switch that has not failed. I just acquired a white paint unit I will be installing. Thinking about what Dave McKeen said, has anyone NOT relocated their inertia switch when replacing it? Jumped plug and not use a switch?
69427

[Bitsyncmaster]

Old thread I know but while searching for inertia switch info I found this thread. My Nov. 81 car has an original switch that has not failed. I just acquired a white paint unit I will be installing. Thinking about what Dave McKeen said, has anyone NOT relocated their inertia switch when replacing it? Jumped plug and not use a switch?
69427

I still use it to shut down my battery one second after the switch breaks. Since my battery shuts off I don't need to run the pump current through the switch.

[David T]

If you use the inertia switch to trip a battery master switch just make sure the inertia switch will still unlock the doors before the battery gets disconnected. Some owners still have that function working. As for relocating the switch, less important on an automatic but still advisable. Especially if you are a big guy. I would not advise jumping out the switch except for testing purposes. It serves an important safety function.

[Bitsyncmaster]

If you use the inertia switch to trip a battery master switch just make sure the inertia switch will still unlock the doors before the battery gets disconnected. Some owners still have that function working. As for relocating the switch, less important on an automatic but still advisable. Especially if you are a big guy. I would not advise jumping out the switch except for testing purposes. It serves an important safety function.

That is why I wait one second. It lets the doors unlock before disconnecting.

[Chris4099]

Old thread I know but while searching for inertia switch info I found this thread. My Nov. 81 car has an original switch that has not failed. I just acquired a white paint unit I will be installing. Thinking about what Dave McKeen said, has anyone NOT relocated their inertia switch when replacing it? Jumped plug and not use a switch?

Here's my opinion on fully performing a recall: DO IT! Relocate the switch! If the problem was severe enough that a struggling start-up car company both noticed the issue early on and spent the money to perform a full recall on it, it's probably a big enough problem to take seriously. About 17 years ago I got into my car and it wouldn't start. Turned out the inertia switch was the pre-recalled version and had failed. I've since replaced and relocated it. I then went on and did all the other recalls that were never done. Front end sway bar brackets, ball joint castle nuts, and double nuts on the sway bar ends.

[Timeless]

It's done.