Brake light switch replacement?

[Timebender]

Hi guys,
My brake light switch has been a bit problematic. At first it was just stuck, and a little WD40 seemed to fix the issue. I noticed the other night my brake lights weren't working again, and so checked the fuse first. It looked fine, but there's a 15 amp vs. 30 (or should it be 20?). So I checked the switch and the plunger was stuck. So I wd40'd it again, and I could see it sparking inside the case, but it on,y did that a few times then stopped.
So I'm guessing it's time for a new switch.
Does Radio Shack have an equivalent, and I'm guessing it's held in with a nut on the plunger side.

Thanks,
Greg

[David T]

Hi guys,
My brake light switch has been a bit problematic. At first it was just stuck, and a little WD40 seemed to fix the issue. I noticed the other night my brake lights weren't working again, and so checked the fuse first. It looked fine, but there's a 15 amp vs. 30 (or should it be 20?). So I checked the switch and the plunger was stuck. So I wd40'd it again, and I could see it sparking inside the case, but it on,y did that a few times then stopped.
So I'm guessing it's time for a new switch.
Does Radio Shack have an equivalent, and I'm guessing it's held in with a nut on the plunger side.

Thanks,
Greg

It is #18 (bottom right side) and it should be a 20 amp fuse. That you can get locally. While you are at it check all of the other fuses to make sure they are the right size. Refer to M:07:03 in your Workshop Manual. They should have put the sizes on the fuseblock cover. You won't find a replacement switch at the Shack. Try your favorite Delorean vendor and you can probably fill out the order with some filters (oil and air) at least. R & R ing the stop light switch M:14:02 Fig 59. There is no spec on adjustment but you should adjust it so when the pedal bracket just touches the plunger it turns off the brake lights.

[Timebender]

Thanks Dave! I actually don't have the fuse block cover, so looks like I should get one.

[Bitsyncmaster]

Thanks Dave! I actually don't have the fuse block cover, so looks like I should get one.

Don't install the fuse box cover over the fuses. The fuses can produce a lot of heat and the cover just makes it worse.

[Timebender]

Got it. I should get the work shop manual though.

[PJ Grady Inc.]

Hi guys,
My brake light switch has been a bit problematic. At first it was just stuck, and a little WD40 seemed to fix the issue. I noticed the other night my brake lights weren't working again, and so checked the fuse first. It looked fine, but there's a 15 amp vs. 30 (or should it be 20?). So I checked the switch and the plunger was stuck. So I wd40'd it again, and I could see it sparking inside the case, but it on,y did that a few times then stopped.
So I'm guessing it's time for a new switch.
Does Radio Shack have an equivalent, and I'm guessing it's held in with a nut on the plunger side.

Thanks,
Greg

The switch is readily available from most venders (including us) for around ten bucks. It's not worth the trouble trying to crossreference it in the interest of saving money. Your biggest problem will be getting the wrench in there at the proper angle to replace it. You'll need a stubby M14 wrench.
Rob

[DMC5180]

Fwiw: not all cars use fuse 18. Some have an inline fuse in harness.

[Timebender]

I bought a Volvo switch just to test if it's the switch that's bad or something else, and it is the switch. And it looks like it might fit where either stock one is. I did order a new one, but have a car show Wednesday I have to go to, and don't want to be driving without brake lights.
So the question is, what tool should I use to loosen the nut on the backside of the plate? It's a very tight spot and I can't get a crescent wrench in there, and normal needle nose pliers are too long.
Maybe angled needle nose pliers, or a teeny tiny vise grip?

[Timebender]

I managed to replace my brake light switch last night with one from a 1981 Volvo- pretty much the same fit though the hole had to be made slightly larger.
No one told me what looked like a 10 minute job would take almost 4 hours. Why 4 hours you may ask?

First, getting the old one out wasn't easy, as the nut that held it was seized. A liberal spray of WD40 kind of helped but not much.
Second, ever try getting a pair of needle nose or very small vice grips in there with the pedals in the way?
Third, if someone told me the DeLorean was built mostly by Leprechauns before I had one I would have thought it was a fun Irish joke about the car being made in Ireland.
Turns out it was built mostly by Leprechauns, as no normal sized person (or normal sized giant in my case) can fit comfortably in there to get the switch out using both hands, and then get the other one in, which was almost impossible. Not completely, but almost.

At the end of my 4 hour journey, I was able to get the nut behind the mount, get the switch in, and turn it to accept the nut, as well as tighten down enough. Hooked up the two wires which went on fine, and now I have brake lights once again.

It should not have taken 4 hours and I'm sure it would have been less had I the shop manual, or some advice here at the least on how to remove and replace it.

Next purchase: Shop manual.

The nice thing about the Volvo switch is it's not cheap plastic.

[Timebender]

Even if I had downloaded the manual, it's not all that helpful.
http://dmctalk.org/attachment.php?attachmentid=36744&d=1441832282
http://dmctalk.org/attachment.php?attachmentid=36745&d=1441832283

Really? Man am I GLAD that I looked it up to see if I did it right...

They obviously forgot to add a disclaimer that all work must be performed BY A LEPRECHAUN...

[DMC5180]

I'm just a little confused by the difficulty loosening nut number 3. With that nut removed the switch should simply slide through the bracket. Was that not the case ?

How did you go about making the hole a little larger?

Also did you remove the seat to gain access? I've always found it much easier to lay on the floor.

[Timebender]

I'm just a little confused by the difficulty loosening nut number 3. With that nut removed the switch should simply slide through the bracket. Was that not the case ?

How did you go about making the hole a little larger?

Also did you remove the seat to gain access? I've always found it much easier to lay on the floor.

Well, it was difficult at best to slide a set of needle nose pliers in there (it's a very very tight space) to even get to the nut, and when I was able to, the nut would move a little bit, but then stop - I tried to hold it steady while turning the switch instead but still no luck and kept dropping the pliers (I'm 6' 7" and pretty big overall, so it's nearly impossible to get both arms/hands in there). Since the game pedal is in the way as well, you don't have a lot of room to turn the pliers, and there's no room for even a 17mm (or 16mm) crescent wrench. So I got some very small vise grips and latched onto the nut, then started to spin the switch to get it to back out, but no luck either as it wouldn't budge without using a wrench, and then the case started to break.
Once I finally had it out, there was still the fun of putting the new one in. I used a drill bit that was the same size as the threaded area of the new switch (well, a tad larger), and bored out the hole slightly.
Then it came to getting the new one in and trying to not drop the nut on the other side. It's very hard to get it almost up flush against the bracket, and not drop it, holding it with one hand as you try and sing the new switch into it. You can't just put the switch in, then slide the nut over it and tighten it as the button is pushing against the brake lever.
And if you get the switch in with the nut in place, my hands were to big to reach in and turn it. And a pair of needle nose pliers again wouldn't fit.
Plus it's too tight to reach with one hand to spin the switch in while holding the nut with something (again not enough room).

I had considered removing the seat, but at that point was too tired and frustrated, even though it would've taken no time probably. And laying on the floor on my back probably would've been easier too.

[DMC5180]

6'7" says it all. I gave a guy a ride in my car who was 6'9". Their was no way he could drive the car because of his knees.


Dennis

[Timebender]

I just fit in mine and that's with the 5 speed as well

[PJ Grady Inc.]

I managed to replace my brake light switch last night with one from a 1981 Volvo- pretty much the same fit though the hole had to be made slightly larger.
No one told me what looked like a 10 minute job would take almost 4 hours. Why 4 hours you may ask?

First, getting the old one out wasn't easy, as the nut that held it was seized. A liberal spray of WD40 kind of helped but not much.
Second, ever try getting a pair of needle nose or very small vice grips in there with the pedals in the way?
Third, if someone told me the DeLorean was built mostly by Leprechauns before I had one I would have thought it was a fun Irish joke about the car being made in Ireland.
Turns out it was built mostly by Leprechauns, as no normal sized person (or normal sized giant in my case) can fit comfortably in there to get the switch out using both hands, and then get the other one in, which was almost impossible. Not completely, but almost.

At the end of my 4 hour journey, I was able to get the nut behind the mount, get the switch in, and turn it to accept the nut, as well as tighten down enough. Hooked up the two wires which went on fine, and now I have brake lights once again.

It should not have taken 4 hours and I'm sure it would have been less had I the shop manual, or some advice here at the least on how to remove and replace it.

Next purchase: Shop manual.

The nice thing about the Volvo switch is it's not cheap plastic.

I guess you didn't see my suggestion about a stubby 14mm wrench? With that (and only that will work) I can do the job in less than a half hour depending on the exact positioning and tightness of the nut. I felt guilty for charging the customer $40- or $50- labor last time I did one because it looks so simple but is so cramped that it takes some time. Now I don't feel guity at all....thank you!
Rob

[Timebender]

No- missed that suggestion Rob... And happy to help you not feel guilty about the labor cost. Danny charges $110 an hour out here, and most non-D shops charge $100 an hour nowadays.

As far as the wrench, doesn't seem like anything I'd find at a local hardware store- though maybe Ace would carry it.

[refugeefromcalif]

As far as the wrench, doesn't seem like anything I'd find at a local hardware store- though maybe Ace would carry it.

Sometimes when I need a Stubby wrench, I'll buy a cheap one and cut it in half. :hihi2:

George

[PJ Grady Inc.]

Sometimes when I need a Stubby wrench, I'll buy a cheap one and cut it in half. :hihi2:

George

I've done that too George. A professional technician needs a good set though which can be Snap-on, Mac, Matco, (probably Facom and Stahlwille as well) or other high end toolmakers.
Rob

[David T]

I've done that too George. A professional technician needs a good set though which can be Snap-on, Mac, Matco, (probably Facom and Stahlwille as well) or other high end toolmakers.
Rob

Yeah but, I have also done that but I hate cutting up an expensive Snap-On (Snap-Off!) wrench. Craftsman is a lot cheaper and if you are only going to use it infrequently it will serve the purpose. I have also bent wrenches for special places but now they sell them all bent up too. They cal them "Water Pump" wrenches and they are bent up into "S" shapes and are double-ended box wrenches. Try to stay away from any of the brands made in China like Cobolt. They can break without much warning and you can get hurt. The open end will spread too.

[PJ Grady Inc.]

Yeah but, I have also done that but I hate cutting up an expensive Snap-On (Snap-Off!) wrench. Craftsman is a lot cheaper and if you are only going to use it infrequently it will serve the purpose. I have also bent wrenches for special places but now they sell them all bent up too. They cal them "Water Pump" wrenches and they are bent up into "S" shapes and are double-ended box wrenches. Try to stay away from any of the brands made in China like Cobolt. They can break without much warning and you can get hurt. The open end will spread too.

What I meant David is if you buy a set of good "Stubbies" you won't need to shorten them as they come that way. I agree that Craftsman are great for the money and I have cut a few uf them in half without guilt but couldn't do that to the high end stuff and sleep well at night.
Rob

[David T]

What I meant David is if you buy a set of good "Stubbies" you won't need to shorten them as they come that way. I agree that Craftsman are great for the money and I have cut a few uf them in half without guilt but couldn't do that to the high end stuff and sleep well at night.
Rob

Most people who will work on their own cars can't or won't afford the good stuff. I don't blame them, they aren't using them everyday making a living at it. They will buy Harbor Freight or some other cheap set of tools from China and it just makes a hard job harder when you don't use the right tool for the job. They won't buy a whole set of stubbies when they can make the one they need. Even stubbies may need to be bent anyway in some cases. On top of that if you don't do this kind of stuff you get stiff and aren't flexible enough to work under the dash above your head where the parts and tools fall on your head. Add to that they can't pick the right size tool just by looking at like an experienced tech would. All of this causes even the smallest job to take a LOT more time and a lot of frustration. Something that would take you 1/2 hour or less does take a novice 4 hours. At least it doesn't cost them 4 hours of labor!

[Timebender]

Yep! I'm used to working on cars in general, and this looked like a 15 minute job at the most. But when my wenches wouldn't fit, I wouldn't fit, the nut being seized, it went from "that'll be cinch" to "I hate small Irish people" along with a number of bruises on my right side.

[David T]

Yep! I'm used to working on cars in general, and this looked like a 15 minute job at the most. But when my wenches wouldn't fit, I wouldn't fit, the nut being seized, it went from "that'll be cinch" to "I hate small Irish people" along with a number of bruises on my right side.

I wouldn't go so far as to blame "small Irish people". The pedal box was probably assembled out of the car and then bolted in. A lot easier to do a lot of things when you are assembling a whole car. The way to make the job easier is to remove the seat and "assume the position". Another trick is to get a short piece of rope lighting and stick it up into the dash. Also either have an assistant to hand you tools or have them laid out where you can reach them so you don't have to keep getting in and out. Doing jobs like this keeps you flexible so you don't have to do Yoga exercises.

[Timebender]

I wouldn't go so far as to blame "small Irish people". The pedal box was probably assembled out of the car and then bolted in. A lot easier to do a lot of things when you are assembling a whole car. The way to make the job easier is to remove the seat and "assume the position". Another trick is to get a short piece of rope lighting and stick it up into the dash. Also either have an assistant to hand you tools or have them laid out where you can reach them so you don't have to keep getting in and out. Doing jobs like this keeps you flexible so you don't have to do Yoga exercises.
Yeah I know- but it being so tiny and cramped in there, it would make a good story that leprechauns were hired to do some work on the car...

Next time the seat is coming out - hopefully I can fit a little better on my back. As far as getting in and out, that wasn't so much to get the tools as I had those on the floor- it was just to rest and then go back in to continue. I finally got somewhat smarter and laid down a big pillow on the sill so I wasn't constantly pressing on my side, though by then it was too late.

[dtavres]

Anyone know what this extra black cylinder is connected to the brake light switch?
3980939810

[Bitsyncmaster]

Anyone know what this extra black cylinder is connected to the brake light switch?
3980939810

Looks like a capacitor but no cap is shown on my schematic.

[dtavres]

Update: http://dmctalk.org/showthread.php?8752-brake-lights&p=191276&viewfull=1#post191276

[PJ Grady Inc.]

Looks like a capacitor but no cap is shown on my schematic.
I don't ever recall seeing an official bulletin or update noting this additional capacitor as well as at the idle micro switch but believe both were added on later VINs to avoid potential AM radio "popping" as these circuits are energized. In other words don't worry about it too much!
Rob

[dtavres]

I don't ever recall seeing an official bulletin or update noting this additional capacitor as well as at the idle micro switch but believe both were added on later VINs to avoid potential AM radio "popping" as these circuits are energized. In other words don't worry about it too much!
Rob
Danny at DMC said it's a noise suppressor... which makes sense combined with your note about the radio.

Thanks :)