What was the primary issue with the door lock modules?

[AirmanPika]

Man I just realized I haven't posted much here in ages...admittedly I haven't done much with my car in the last year either.

Anyway, I was curious what the common issue was regarding the door lock modules. Was there a specific component on them that failed over time? I disconnected mine based on recommendations here but in all honestly the modules are not hard to work on. I've been rebuilding old vintage amps the last few months and the boards in the module are quite simple. I figure if there were common failure parts I could just replace those and then the module should be good for another 20 or so years. The capacitors are an obvious choice because of age but was there any undue stress on any other parts?

[jawn101]

Man I just realized I haven't posted much here in ages...admittedly I haven't done much with my car in the last year either.

Anyway, I was curious what the common issue was regarding the door lock modules. Was there a specific component on them that failed over time? I disconnected mine based on recommendations here but in all honestly the modules are not hard to work on. I've been rebuilding old vintage amps the last few months and the boards in the module are quite simple. I figure if there were common failure parts I could just replace those and then the module should be good for another 20 or so years. The capacitors are an obvious choice because of age but was there any undue stress on any other parts?

The relays would burn and stick, and the transistors would draw way too much power (old technology)

Elvis has a guide on how to rebuild the modules and it works fantastically. Just replace two transistors and two resistors, and your relays if they are burned/worn already.

[Jonathan]

What I remember hearing was related to the 80s technology in our cars not having "limit switches" or feedback if you will. Meaning, if you keep pressing the window button to go up, it will keep trying to force the window up and burn out the motor. Newer cars are smart enough to know they are already all the way up and don't keep trying to push the window up even further.

Our door lock system won't realize your door isn't shut all the way or properly enough to be aligned, and then will keep firing the lock solenoid trying to get it to lock that it will burn itself out. I was led to believe this is the sort of scenario that can get you locked in your car.

Is that urban myth, or is that true? I've repeated it a few times at shows or in conversation...

[David T]

What I remember hearing was related to the 80s technology in our cars not having "limit switches" or feedback if you will. Meaning, if you keep pressing the window button to go up, it will keep trying to force the window up and burn out the motor. Newer cars are smart enough to know they are already all the way up and don't keep trying to push the window up even further.

Our door lock system won't realize your door isn't shut all the way or properly enough to be aligned, and then will keep firing the lock solenoid trying to get it to lock that it will burn itself out. I was led to believe this is the sort of scenario that can get you locked in your car.

Is that urban myth, or is that true? I've repeated it a few times at shows or in conversation...

The main problem with the door lock module is that the relay contacts can't handle the inrush current of the solenoids in the doors. Eventually the contacts will weld themselves together making it impossible to interrupt the current to the solenoids. The circuit breaker is too big to trip so the current flows until it melts the windings in the solenoids and kills the battery. In the meantime you can't unlock the doors to get out. The other minor problem is the type of transistors used have a high current draw so if the car is not used for a long time it can deplete the battery. There are many ways that have been used to overcome these problems, from disconnecting it to modifying it to changing it. Another common problem is if the door linkage is not adjusted properly or gets forced, one door can be in second locking position and the other is not. Someone tries to force a door locked and bends the linkage. Now the door lock module is "confused" and *should* unlock the doors when you try to lock them. Doesn't always happen. If you still have the original central door locking system and have not done anything to it the best advice is to disconnect the big red wire. If you insist on having it work then at the very least you should cut an in-line fuse into that big red wire with a 10 amp fuse inside. BTW, chances are the solenoids in your doors are already damaged. Modifying the module can't fix that. Your choices are to rewind them (there is a good write-up for that) replace them with OEM, or replace them with actuators.
David Teitelbaum

[jawn101]

The actuators are a great upgrade. Also the lock and latch alignment process is a must. If you do the actuators and rebuild the OEM lock module to Elvis' specs my understanding is there is really no need for the inline fuse to the lock module.

[Jonathan]

Thanks for the explanation David.

Perhaps also worth mentioning here is how the door locks are tied into the inertia switch wiring. If your inertia switch goes off in an accident, it will kill the fuel pump and it will also unlock the doors (your car would need your door lock module to be plugged in of course and things working as mentioned above).

What I learned from another owners experience last winter was that if you raise the plunger on the inertia switch manually while it is stored for the season as a "security" type measure, your doors will unlock themselves and they won't let you lock them again. Which would kind of defeat the extra theft deterant of not being able to start the car/fuel pump with the inertia switch triggered by having the doors unlocked. You could do this if your door lock module is disconnected and you unlock your doors manually, but not if it was plugged in.

Just a little oddity with the car someone else might stumble upon...

[WelmoedJ]

Thanks for the explanation David.

Perhaps also worth mentioning here is how the door locks are tied into the inertia switch wiring. If your inertia switch goes off in an accident, it will kill the fuel pump and it will also unlock the doors (your car would need your door lock module to be plugged in of course and things working as mentioned above).

What I learned from another owners experience last winter was that if you raise the plunger on the inertia switch manually while it is stored for the season as a "security" type measure, your doors will unlock themselves and they won't let you lock them again. Which would kind of defeat the extra theft deterant of not being able to start the car/fuel pump with the inertia switch triggered by having the doors unlocked. You could do this if your door lock module is disconnected and you unlock your doors manually, but not if it was plugged in.

Just a little oddity with the car someone else might stumble upon...

+1
A defective inertia switch (stuck closed, alike car rolled on its back) also causes the doors to stay unlocked.

Regarding rebuilding/repairing the lock module:
Some of the diodes can be blown if the module isn't working.
The capacitors also are "over sized"; installing a lesser capacity will also help.

[David T]

+1
A defective inertia switch (stuck closed, alike car rolled on its back) also causes the doors to stay unlocked.

Regarding rebuilding/repairing the lock module:
Some of the diodes can be blown if the module isn't working.
The capacitors also are "over sized"; installing a lesser capacity will also help.

If you are storing your car then you either have the battery master switch off and/or you have disconnected and removed the battery. Door lock module isn't going to work now. I know the inertia switch is supposed to unlock the doors but I have never tested it. Of course that depends on a good working central door locking system AND inertia switch. I have seen a LOT of Deloreans that never got the recall for the switch done and I have seen a lot where the wiring got hacked up because of problems with the fuel pump. Point is for that unlock feature to work everything has to be in working order.
David Teitelbaum

[WelmoedJ]

If you are storing your car then you either have the battery master switch off and/or you have disconnected and removed the battery. Door lock module isn't going to work now. I know the inertia switch is supposed to unlock the doors but I have never tested it. Of course that depends on a good working central door locking system AND inertia switch. I have seen a LOT of Deloreans that never got the recall for the switch done and I have seen a lot where the wiring got hacked up because of problems with the fuel pump. Point is for that unlock feature to work everything has to be in working order.
David Teitelbaum

I agree with most of what you write.
However having upgraded the lock module and replaced the solenoids I never saw the need for disconnecting the battery.
Disconnecting the battery also disables the alrm system (though it could be working if still connected to the battery).

I leave the battery connected all the time as I often use the car.
Even after a month or two of rest it still is able to start and run (regardless of the alarm and other parts powered).

[wrkey]

Very interesting thread here and great information from all. On my car (Della) the driver's side door functions as it should but the passenger side does not. Attempts to lock the passenger side door is met with a large amount of resistance so I am assuming that either A)it is stuck with old grease and dirt or B)out of adjustment. I have been 'ignoring' this condition because I seldom lock my car. However, reading this thread makes me reconsider by reasoning and perhaps I should see if i can resolve the issue with the passenger door.

So, two questions (for now) how do I access the locks (I've never removed the door panels) and where is the control module located? I'm sure there is a 'how to' on here somewhere to pull the panels but I haven't done that search yet.. but is pulling the inner door panel all I need to do access the locking system or is there more to it? I'm pretty sure I can effectively rebuild the module but in reading about "Elvis's" replacement, I'm thinking I might go that route depending upon cost. Can someone give me more info on where to find this upgrade?

Thanks in advance!

Rusty

[jawn101]

Very interesting thread here and great information from all. On my car (Della) the driver's side door functions as it should but the passenger side does not. Attempts to lock the passenger side door is met with a large amount of resistance so I am assuming that either A)it is stuck with old grease and dirt or B)out of adjustment. I have been 'ignoring' this condition because I seldom lock my car. However, reading this thread makes me reconsider by reasoning and perhaps I should see if i can resolve the issue with the passenger door.

So, two questions (for now) how do I access the locks (I've never removed the door panels) and where is the control module located? I'm sure there is a 'how to' on here somewhere to pull the panels but I haven't done that search yet.. but is pulling the inner door panel all I need to do access the locking system or is there more to it? I'm pretty sure I can effectively rebuild the module but in reading about "Elvis's" replacement, I'm thinking I might go that route depending upon cost. Can someone give me more info on where to find this upgrade?

Thanks in advance!

Rusty

The Elvis method is a modification to the OEM module that makes it much more reliable, durable and battery-friendly. I did the mod with enough parts left over to do a second one for under $5.

Details of it can be found here: www.dmcnews.com/Techsection/pdfs/lockmod91.pdf‎ - all you need are some resistors, transistors, possibly relays, and some basic soldering tools/skills.

Or you can go with the digital modules from the DMC vendors, they are much more expensive but thoroughly modern. And they provide additional features like keyless entry, alarm inputs, etc. Personally, I'd do it the Elvis way first, then take the money you saved and dump it into the DPNW actuators. http://www.delorean-parts.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=DPNW&Product_Code=K2500DP-CS&Category_Code=9401

Definitely look at the lock and latch adjustment. The adjustment procedure is here: http://www.dmcnews.com/bulletins/ST-10-8.81.pdf

Removing the door panels is easy. Details are in the service manual, I believe.

[kings1527]

So, two questions (for now) how do I access the locks (I've never removed the door panels) and where is the control module located? I'm sure there is a 'how to' on here somewhere to pull the panels but I haven't done that search yet.. but is pulling the inner door panel all I need to do access the locking system or is there more to it? I'm pretty sure I can effectively rebuild the module but in reading about "Elvis's" replacement, I'm thinking I might go that route depending upon cost. Can someone give me more info on where to find this upgrade?

Thanks in advance!

Rusty

I did a write-up on installing a new digital door lock module and installing actuators. I also went over how to get the door panels off. Overall, both operations are very easy to do with the right tools (long extension, large flat head screwdriver, etc. Basic stuff).

http://delorean6575revisited.blogspot.com/2013/05/installing-dpnws-door-actuators-digital.html

[Marigolo]

Hi, hopefully this question belongs in this thread.
I just wanted to know what the red and green lights on the module indicate and what the small black button is... I can't find any info online :rolleyes1: Anybody have a clue?
Thanks!
Mario.

[Rich]

So, two questions (for now) how do I access the locks (I've never removed the door panels) and where is the control module located?

About the door lock module location in case it was not answered or not found so far:

Look at this wiring thread and scroll down to Door Lock Circuit:

http://dmctalk.org/showthread.php?40-All-Wiring-Schematics

You'll see it blacked out in the location diagram which shows the layout of all of the electricals in the access area beneath the rear parcel shelf behind the passenger seat.

[WelmoedJ]

Hi, hopefully this question belongs in this thread.
I just wanted to know what the red and green lights on the module indicate and what the small black button is... I can't find any info online :rolleyes1: Anybody have a clue?
Thanks!
Mario.

The original or rebuilt original lock modules don't have lights or switches on them.
Could be that you have either a Lockzilla unit (I never saw one, so can't confirm about lights/switches) or something else.
Not sure if DMCH has a new one.

[jawn101]

...

Details of it can be found here: www.dmcnews.com/Techsection/pdfs/lockmod91.pdf - all you need are some resistors, transistors, possibly relays, and some basic soldering tools/skills.

...


Not sure what happened to the above link, but it had some crazy characters at the end that were making it not function. Here it is again: http://www.dmcnews.com/Techsection/pdfs/lockmod91.pdf

[Marigolo]

The original or rebuilt original lock modules don't have lights or switches on them.
Could be that you have either a Lockzilla unit (I never saw one, so can't confirm about lights/switches) or something else.
Not sure if DMCH has a new one.

http://store.delorean.com/p-7206-door-lock-control-unit-digital.aspx

This is the one I'm talking about... The (New) Digital control unit. Green and red lights and a little button that looks like some sort of "reset" button.

[Patrick C]

http://store.delorean.com/p-7206-door-lock-control-unit-digital.aspx

This is the one I'm talking about... The (New) Digital control unit. Green and red lights and a little button that looks like some sort of "reset" button.

Wasn't there a version that was "Zelda Gold" at one point?

[DMCMW Dave]

Hi, hopefully this question belongs in this thread.
I just wanted to know what the red and green lights on the module indicate and what the small black button is... I can't find any info online :rolleyes1: Anybody have a clue?
Thanks!
Mario.

The button is indeed a reset button.

The green lights tell you that the lock successfully locked. A red light tells you that the lock didn't lock, so it backed off so as to not lock you in the car or jam. It tells you which one but they are not labeled. I don't have the sheet handy that tells which is which, but if you watch the lights as you hear the doors attempt to lock/unlock you can tell, as there is a delay between the left and right.

[Marigolo]

The button is indeed a reset button.

The green lights tell you that the lock successfully locked. A red light tells you that the lock didn't lock, so it backed off so as to not lock you in the car or jam. It tells you which one but they are not labeled. I don't have the sheet handy that tells which is which, but if you watch the lights as you hear the doors attempt to lock/unlock you can tell, as there is a delay between the left and right.

Wonderful!
Thank you :-)

[DCUK Martin]

Elvis' write-up on the original lock module is very good for improving the standby current, but he merely says "replace the relays".

The problem is that the original relays are open to the air, and being switched wth a charged capacitor is like turning off a light switch very slowly, as the contacts move apart slowly, they're very prone to sparking. With a large inductive device hanging off the relay makes for oxidation and getting stuck shut very quickly.

I replace them with these tiny little hermetically sealed 25A(inductive load) relays. Hermetically sealed means that they can spark as much as they like, they can't oxidise and get stuck.

http://uk.farnell.com/jsp/search/productdetail.jsp?sku=9659013

These have a fairly low coil resistance meaning the switch time is similar to the originals - about a second. No need to down-rate the main capacitors.

I'm very glad that at no point in this thread has anyone said that the solenoids are unreliable. They are 100% reliable (in Jaguar circles, they have a bulletproof reputation) as long as the control module has been upgraded.

I got to #1458 before the solenoids were toasted (the vast majority of originals are). 13 years and some 40k miles later the solenoids are still working just fine, as is the module I rebuilt.

I re-wind original solenoids occasionally (they are on my website) to make them good as new. I personally don't kike the actuators because in my view there is nothing wrong with the original solenoids' design. But I understand that they're no longer available and the vast majority out there are toast. I like the solid "thunk" they make when they work properly :smile:

[Ryan S.]

Elvis' write-up on the original lock module is very good for improving the standby current, but he merely says "replace the relays".

The problem is that the original relays are open to the air, and being switched wth a charged capacitor is like turning off a light switch very slowly, as the contacts move apart slowly, they're very prone to sparking. With a large inductive device hanging off the relay makes for oxidation and getting stuck shut very quickly.

I replace them with these tiny little hermetically sealed 25A(inductive load) relays. Hermetically sealed means that they can spark as much as they like, they can't oxidise and get stuck.

http://uk.farnell.com/jsp/search/productdetail.jsp? (http://uk.farnell.com/jsp/search/productdetail.jsp?sku=9659013)

Martin, thanks for your posting and sorry for my ignorance. Where do you exactly put this relay in and/or which relay is this replacing???

[DrJeff]

...Where do you exactly put this relay in and/or which relay is this replacing???

If you open up the Door Lock Module (DLM), you will find something similar to the attached photo. This DLM has had the Elvis Mod done so the transistors and two resistors are changed. The photo does show the two original relays. The relays are the two components at the bottom left and right of the picture (copper windings, switches, and small springs). These relays can be replaced with a sealed relay. My replacement sealed relays (not shown in this photo) were a little too large (taller) than the space within the DLM - which makes the cover of my DLM not fit 100% - but a small compromise.

21588

[David T]

If you open up the Door Lock Module (DLM), you will find something similar to the attached photo. This DLM has had the Elvis Mod done so the transistors and two resistors are changed. The photo does show the two original relays. The relays are the two components at the bottom left and right of the picture (copper windings, switches, and small springs). These relays can be replaced with a sealed relay. My replacement sealed relays (not shown in this photo) were a little too large (taller) than the space within the DLM - which makes the cover of my DLM not fit 100% - but a small compromise.

21588


I like the solenoids too and they can be rewound but the actuators have 2 big advantages, they draw a lot less current and they are at least one spline lighter on the torsion bars.
David Teitelbaum

[BABIS]

Elvis' write-up on the original lock module is very good for improving the standby current, but he merely says "replace the relays".

The problem is that the original relays are open to the air, and being switched wth a charged capacitor is like turning off a light switch very slowly, as the contacts move apart slowly, they're very prone to sparking. With a large inductive device hanging off the relay makes for oxidation and getting stuck shut very quickly.

I replace them with these tiny little hermetically sealed 25A(inductive load) relays. Hermetically sealed means that they can spark as much as they like, they can't oxidise and get stuck.

http://uk.farnell.com/jsp/search/productdetail.jsp?sku=9659013

These have a fairly low coil resistance meaning the switch time is similar to the originals - about a second. No need to down-rate the main capacitors.



Martin, these relays can be used with the "Elvis" modification?

[Bitsyncmaster]

The problem is that the original relays are open to the air, and being switched wth a charged capacitor is like turning off a light switch very slowly, as the contacts move apart slowly, they're very prone to sparking. With a large inductive device hanging off the relay makes for oxidation and getting stuck shut very quickly.

+1

That is the real fault of the design. Not using a switching +12 to 0 volt or 0 volt to +12 signal is almost a guarantee the contacts will burn.

[Ryan S.]

If you open up the Door Lock Module (DLM), you will find something similar to the attached photo. This DLM has had the Elvis Mod done so the transistors and two resistors are changed. The photo does show the two original relays. The relays are the two components at the bottom left and right of the picture (copper windings, switches, and small springs). These relays can be replaced with a sealed relay. My replacement sealed relays (not shown in this photo) were a little too large (taller) than the space within the DLM - which makes the cover of my DLM not fit 100% - but a small compromise.

21588
Jeff, thanks for your explanations. So is there relay sockets where I can just plug the new relays or do I need to soder them in?

[DrJeff]

Jeff, thanks for your explanations. So is there relay sockets where I can just plug the new relays or do I need to soder them in?

They need to be soldered in. Getting the old relays out is the biggest pain. Bitsyncmaster may have a good way of doing this. They have 5 pins/connections to the main board. If your board is anything like mine there will be an abundance of solder already on them. I heated the existing solder on the joints, one at a time, and slowly edged the old relays away from the board until they were free. Putting the new ones in is easy by comparison.

[DSNW Toby]

http://store.delorean.com/p-7206-door-lock-control-unit-digital.aspx

This is the one I'm talking about... The (New) Digital control unit. Green and red lights and a little button that looks like some sort of "reset" button.

Mario - I have an illustrated guide to what the various lights mean ... I will send you a copy if you let me know what your email is. They light up to indicate proper functioning, or fault codes of something is wrong in your locking system. That little button is actually used to initiate the internal diagnostic procedure in the module. With both doors completely closed, or open with the latches set to the closed position (I can explain this as well), the module will operate the entire central locking system in an elaborate test sequence and tell you what parts of the system aren't working correctly.

[Marigolo]

Mario - I have an illustrated guide to what the various lights mean ... I will send you a copy if you let me know what your email is. They light up to indicate proper functioning, or fault codes of something is wrong in your locking system. That little button is actually used to initiate the internal diagnostic procedure in the module. With both doors completely closed, or open with the latches set to the closed position (I can explain this as well), the module will operate the entire central locking system in an elaborate test sequence and tell you what parts of the system aren't working correctly.

PM sent. Thank you!!!

[DCUK Martin]

Martin, these relays can be used with the "Elvis" modification?

Pretty much any relays can. You have to put in jump-wires though because the pin-out is different They're physically much smaller though so there's plenty of room.


I like the solenoids too and they can be rewound but the actuators have 2 big advantages, they draw a lot less current and they are at least one spline lighter on the torsion bars.


Why is the high current a problem IF the module has been beefed up to accomodate it? For the second or so that they're on, the amount of energy consumed is still very small and all the wiring is of a more than appropriate gauge.

That they make the doors fractionally lighter is incidental IMO. Mostly, torsion bars break when they've been over-torqued to account for a weak strut and/or are rubbing where the steel roof comes unstuck and flexes skyward, catching on the bar.

[Elvis]

I missed this thread with 100 times my name in it ? :-)
Well I was on the tour de france when it started.

The writeup is pretty old and I updated it - at least here on my harddisk,
but never officially released a finished one yet.
But - if you PM me - I will email it to you interested guys.

Good time to finish a new version ?!?


First of all - install that 10A fuse in the fat red wire !!!!!!!!!!!!!


I offer kits to update these ECUs, but I stopped offering them here after I made
bad experience.
Usually I get the ECUs, update and test them, install a remote unit and send them back.

Relays - they absolutely need to be changed !!!

The ones I use are cheap and more reliable than the original BOSCH ones.
Sealed ones ? try mine and if the fuse ever burns - then you have a reason
to go with the sealed ones.
After 50 units I only had problems with cars that already had burned solenoids,
which is very common. (fuse burns, nothing more)
or it has mechanical issues,
one bad inertia switch,
and once I thought I could keep the orginal relays as they looked brandnew.
Locked and unlocked it 5-10 times - fuse was burned as the relay was sticking.
Swapped it with my relays - problem gone !

We used these transistors at work, I have many of them left.
Resistors are cheap, I have them here.
A good fuse holder with the correct easy-unplug connector is also available, I
always buy 10-20 of them.

This is how the ECU looks like when I'm done with them and the connector for the
remote is installed:

21613.

If you are interested in remote units to lock and unlock the doors with the kit - PM me.


I always read about replacing diodes and capacitors. If you want to know my opinion:
Don't touch them !

There is always one burned diode when I get untouched ECUs: cut it out and leave it away !
If I ever get a feedback of a car that has a problem because of that "missing"
diode - I will post it and repair it for free !
A protection-diode that burns...well what protection is that ? You want to install it
again to let it burn again ? I don't.
Experience shows - this tale comes up again and again - so do whatever you believe more.



BTW - I also modified Zilla and a Delorean One unit.
They also needed the current saving update...they just copied the original flawed schematic !!!!!

Why do the relays fail by sticking ?
Often repeated, different opinions, believe whatever you want, but this is my theory:

The relays are driven by discharging the capacitors. With 12V fully charged capacitor delivers
a lot of current (which means force) to drive the relay, the switch is closed quickly.
But now the capacitor discharges, the voltage and current to hold the switch of the relay sinks,
the force to keep it closed sinks accordingly and when the voltage drops below ~5V eventually
the relay opens by the spring.
But it does not open quickly, it's rather slow.
And exactly here is the problem ! The original relays would work fine if they were turned on
and off fast. Opening slowly allows the arc to weld it together.
This all happens within about half a second. When watching it all it does is - click click.

Does my kit/mods change how the ECU works ? No, but 10 years experience show - the new
relays work reliable. If there shoudl aver by a problem - there is the fuse which protect the
circuit after only 2-3 seconds.
And - when I picked up my car this weekend after 4-5 weeks of not driving it (summer was
great I drove the roadster) - the DMC started right away - without disconnecting the battery :-)

PM me if you need more details, kits or remotes.

Elvis & 6548

[AirmanPika]

Well that was certainly informative. I appreciate all the inputs. I'll prolly rebuild my module and see how the system works. Of course the solenoids have been disconnected for so long I'll be amazed if they haven't seized.