Door Lock Issue

[DavidProehl]

The original door lock module and solenoids on the DeLorean are prone to failure, and I have both.

A little background:

I was piecing my interior back together after replacing my evaporator, and heard a POP sound from the fuse area when hooking up my cigar lighter. Sure enough, I blew the fuse for the cigar lighter. The funny thing was however, was that I also was no longer getting a lit "Lock Doors" light on the A/C panel display when I had the key in the ignition. I know that light was coming on 30 minutes prior. I replaced the cigar lighter fuse, but still the lock doors light wouldn't come on (not surprising, wouldn't expect them to be related).

What was surprising was that my power locks no longer work. I can lock and unlock both doors with the key, but no power. I hadn't used the locks in a long while (2-3 months), but the last time I did I know the power locks functioned correctly.

So did I somehow also short out the lock module or other wiring while hooking up my cigar lighter? The fact that the door light went off at the same time I blew the cigar fuse seems suspect but I don't see how the two could be related.

Any ideas on how I could test each component (module, solenoids, etc) to troubleshoot?

[Ron]

Check for power at:
Fuse #10 (If fuel pump runs you're ok here ;-)
Door Lock Thermal Trip (It's the one in the back by itself.)
Door Lock Relay Socket's Solid Brown and Brown/Pink wires (and Ground at Black wire)

[DavidProehl]

Sorry for the delayed response, this thread got unintentionally neglected during my move out west.

I verified the power on the wires as you suggested, it checked out fine. The door lock thermal trip you mentioned however I think I'm missing (though my locks were working fine without it). I assume that is what goes in my empty white socket in the far back?

9809

With the cover off, I'm able to hear my lock module click when I manually lock the door, I just don't have any action from either of the solenoids, but I can hear a slight engagement from them when I plug in my lock module. I'm leaning towards it being a bad lock module but the fact that I hear it click makes me second guess that. I was also reading in this DML thread (http://autos.groups.yahoo.com/group/dmcnews/message/8261?&start=8236) that the "lock doors" light could cause problems, but I'm not sure what the symptoms would be. I did have my control panel face off at the time my locks stopped working.

[deloumis]

Sorry for the delayed response, this thread got unintentionally neglected during my move out west.

I verified the power on the wires as you suggested, it checked out fine. The door lock thermal trip you mentioned however I think I'm missing (though my locks were working fine without it). I assume that is what goes in my empty white socket in the far back?

9809

With the cover off, I'm able to hear my lock module click when I manually lock the door, I just don't have any action from either of the solenoids, but I can hear a slight engagement from them when I plug in my lock module. I'm leaning towards it being a bad lock module but the fact that I hear it click makes me second guess that. I was also reading in this DML thread (http://autos.groups.yahoo.com/group/dmcnews/message/8261?&start=8236) that the "lock doors" light could cause problems, but I'm not sure what the symptoms would be. I did have my control panel face off at the time my locks stopped working.

The one in the back should be empty, IIRC, but i couldn't tell you which is the correct relay to look at.
Try checking this diagram to help you out.
http://dmctalk.org/showthread.php?2975-Relays-and-Fuses

[Ron]

I assume that is what goes in my empty white socket in the far back? No, that's the Hot Start Relay Socket (Unused). See below...

9814

If you unpug the Lock Module and ground the Brown-Pink wire (harness side, key ON), does the telltail lamp light.
Have you disturbed the wires going to the mode switch since everything worked?

[mluder]

No, that's the Hot Start Relay Socket (Unused). See below...

9814


Quick interjection...
Iv'e only had my car a year but my Hot Start Relay socket has a relay plugged into it. I currently have difficulty with hot starts (two or thress turns of the key gets it running eventually) but if I remove this relay , car will not hot start at all.
Does this mean something? Why would there be something plugged in here if it's typically unused?

Thanks.
Steven

[AdmiralSenn]

Quick interjection...
Iv'e only had my car a year but my Hot Start Relay socket has a relay plugged into it. I currently have difficulty with hot starts (two or thress turns of the key gets it running eventually) but if I remove this relay , car will not hot start at all.
Does this mean something? Why would there be something plugged in here if it's typically unused?

Thanks.
Steven

The general consensus has been that the socket was never fully wired in from the factory, but there have been a number of PO mods (and possibly QAC mods or undocumented factory tweaks) where it's been wired in to function.

It shouldn't be needed, and if it is there's usually something else wrong with the system. You'll see most of the gurus here recommend against using it to fix a hot start problem except in some sort of emergency situation.

[DavidProehl]

No, that's the Hot Start Relay Socket (Unused). See below...

9814

If you unpug the Lock Module and ground the Brown-Pink wire (harness side, key ON), does the telltail lamp light.
Have you disturbed the wires going to the mode switch since everything worked?

Thanks! That is very helpful to know where the hot start relay would be located. No, haven't disturbed any wires. Strange thing tonight. Took the car out, and manually locked the doors with the key, both individually. Then, I unlocked the passenger side door first and the power locks kicked in to unlock the driver side!

So, something is definitely wrong with my driver's side door. Must be my locking linkages. I've heard from jawn101 that I should probably walk through the service bulletin (http://www.dmcnews.com/bulletins/ST-10-8.81.html)steps to ensure my driver's lock is setup properly. Maybe that is all it will take.

[jawn101]

If the solenoids are working intermittently like that then they could just be burned out. Pretty common. Have you cleaned the wiper switches? Do that while you have the panels off too :)

[DavidProehl]

Following up on this, think I've made significant progress:

My linkages are now aligned and locks are operating properly manually. Power locks only work in one direction for both doors though (unlock).



Solenoids are good - I jumpered one and it locked & unlocked properly
Putting a multimeter on the red/gray wire connected to the lock module and the red/gray wire running from the door to the solenoid shows 0.9 ohm resistance (proves the wire in the harness doesn't have a break)
I have the OEM lock module, and I can hear the relay click both when locking and unlocking


At this point I'm thinking it must be the lock module since I know my solenoids and wiring are good. Does that pass your gut check? Is it weird that I'd hear the relay click in the lock module but not get it to fire?

[jawn101]

Following up on this, think I've made significant progress:

My linkages are now aligned and locks are operating properly manually. Power locks only work in one direction for both doors though (unlock).



Solenoids are good - I jumpered one and it locked & unlocked properly
Putting a multimeter on the red/gray wire connected to the lock module and the red/gray wire running from the door to the solenoid shows 0.9 ohm resistance (proves the wire in the harness doesn't have a break)
I have the OEM lock module, and I can hear the relay click both when locking and unlocking


At this point I'm thinking it must be the lock module since I know my solenoids and wiring are good. Does that pass your gut check? Is it weird that I'd hear the relay click in the lock module but not get it to fire?

Bring it over. You can try my lock module and I have spare solenoids too. :)

[DavidProehl]

Bring it over. You can try my lock module and I have spare solenoids too. :)

Thanks! That would be very helpful. I'm headed to Yosemite this weekend, but I'll find some time.

[DMCMW Dave]

Did you try to activate them manually from the lock module? Take the cover off and manually press the relays (with the doors closed or he latches tripped to the closed position).

[DavidProehl]

Dave - I hadn't tried that yet, but just did now. Same result. Manually tripping the unlock relay fires the solenoids, doing the same to the lock relay has no effect. I can see when operating the locks that the relay is making contact on its own.

Now that I have the unit open I can see it is two distinct sections on the module board, one for unlock and one for lock. It would seem to make sense that a transistor or another component on the lock side of the board is burned out or otherwise broken right? I'm tempted to just order your new digital lock module tomorrow if the odds say that is the problem.

[DMCMW Dave]

Dave - I hadn't tried that yet, but just did now. Same result. Manually tripping the unlock relay fires the solenoids, doing the same to the lock relay has no effect. I can see when operating the locks that the relay is making contact on its own.

Now that I have the unit open I can see it is two distinct sections on the module board, one for unlock and one for lock. It would seem to make sense that a transistor or another component on the lock side of the board is burned out or otherwise broken right? I'm tempted to just order your new digital lock module tomorrow if the odds say that is the problem.

Are you saying that "lock" has no effect on both doors? I misunderstood the original symptom then. Try feeding 12V to the appropriate color wire with the module disconnected, that will tell you if it is a wiring problem or a module problem (see schematic, I don't have the colors quite memorized but it is the red ones with various stripe colors on the large plug). The lock and unlock wire to each solenoid makes an appearance at that plug so you can pretty quickly isolate any in-car wiring issues.

[vwdmc16]

David, I bought the Digital module from Houston years ago, I spent like 1/2 an hour trying to get the stock module to work and decided it was pointless, The digital module has Never failed and has the keyless interface which is so nice and keeps the lock cylinders from wearing out.

[Ron]

Are you saying that "lock" has no effect on both doors? I misunderstood the original symptom then. Try feeding 12V to the appropriate color wire with the module disconnected, that will tell you if it is a wiring problem or a module problem (see schematic, I don't have the colors quite memorized but it is the red ones with various stripe colors on the large plug). The lock and unlock wire to each solenoid makes an appearance at that plug so you can pretty quickly isolate any in-car wiring issues.
+1

=======
You checked the Red/Grey (actually Red/Slate, there are 2, one for each solenoid), but you need to do as Dave suggest above with the two Red/Pink wires to test them. If they work the solenoids, then I'd take the trip to Jon's ;-)
(It may make things clearer if you consider that the solenoids are not reversed by the switch-module, they each have two windings, one open and one lock, with a common ground...)

[DavidProehl]

Are you saying that "lock" has no effect on both doors? I misunderstood the original symptom then. Try feeding 12V to the appropriate color wire with the module disconnected, that will tell you if it is a wiring problem or a module problem (see schematic, I don't have the colors quite memorized but it is the red ones with various stripe colors on the large plug). The lock and unlock wire to each solenoid makes an appearance at that plug so you can pretty quickly isolate any in-car wiring issues.

Yes, that is what I am saying, lock has no effect on both doors. I did as you suggested, found the different "lock" and "unlock" wires and then applied 12V to them. Both worked. This confirms it is the lock module. Looks like I'll be giving Julee a call!


David, I bought the Digital module from Houston years ago, I spent like 1/2 an hour trying to get the stock module to work and decided it was pointless, The digital module has Never failed and has the keyless interface which is so nice and keeps the lock cylinders from wearing out.

Sounds like the way to go. I'll be ordering one today, though I'll probably wait on the keyless entry option for now.

[Elvis]

Dave - I hadn't tried that yet, but just did now. Same result. Manually tripping the unlock relay fires the solenoids, doing the same to the lock relay has no effect. I can see when operating the locks that the relay is making contact on its own.

Now that I have the unit open I can see it is two distinct sections on the module board, one for unlock and one for lock. It would seem to make sense that a transistor or another component on the lock side of the board is burned out or otherwise broken right? I'm tempted to just order your new digital lock module tomorrow if the odds say that is the problem.


Burned Solenoid !

like 75% of all cars have ! very common an well known problem.
This is why we repeat about once a week - install a 10Amp fuse in the fat red wire to prevent
the solenoids from burning!

The other lock module will not fix a burned solenoid.

But as you say applying 12V to the solenoids will make it work - this would mean the connector or
solder joint to the relay is bad. That should be a very easy fix.
But I've never seen this and I modified around 50 lock modules so far...

[DavidProehl]

Burned Solenoid !

like 75% of all cars have ! very common an well known problem.
This is why we repeat about once a week - install a 10Amp fuse in the fat red wire to prevent
the solenoids from burning!

The other lock module will not fix a burned solenoid.

But as you say applying 12V to the solenoids will make it work - this would mean the connector or
solder joint to the relay is bad. That should be a very easy fix.
But I've never seen this and I modified around 50 lock modules so far...

Well, I'll get an answer soon. I ordered the new lock module from DMC Midwest, should be at my door on Thursday. Even if that turns out not to be the root problem, it sounds like it is an upgrade that is well worth doing and eliminates a potential failure point. I'll likely add the keyless entry feature later on once I get my locks working properly.

[jawn101]

Well, I'll get an answer soon. I ordered the new lock module from DMC Midwest, should be at my door on Thursday. Even if that turns out not to be the root problem, it sounds like it is an upgrade that is well worth doing and eliminates a potential failure point. I'll likely add the keyless entry feature later on once I get my locks working properly.

Well if you're pitching money at the problem, I'll give another plug to the DPNW actuator upgrade... some of the best money I've spent. They won't burn or wear out, work quicker and reduce the weight of the doors significantly. Drop in upgrade, takes about 15 minutes per door.

[DavidProehl]

Well if you're pitching money at the problem, I'll give another plug to the DPNW actuator upgrade... some of the best money I've spent. They won't burn or wear out, work quicker and reduce the weight of the doors significantly. Drop in upgrade, takes about 15 minutes per door.

I was thinking about those as well, but since I'm able to fire my solenoids both directions manually I'm pretty confident this isn't blindly throwing money at the issue. In the event I'm wrong, I'll look at actuators. Although if I were lighten the door I'd probably want to weigh it down with some sound proofing or something otherwise I'll need another torsion bar adjustment. The first time around was painful enough.

[jawn101]

I was thinking about those as well, but since I'm able to fire my solenoids both directions manually I'm pretty confident this isn't blindly throwing money at the issue. In the event I'm wrong, I'll look at actuators. Although if I were lighten the door I'd probably want to weigh it down with some sound proofing or something otherwise I'll need another torsion bar adjustment. The first time around was painful enough.

Oh I don't think you're wrong :) Just saying, the actuators are way nicer than the solenoids. Might as well make it a system-wide overhaul while you're in there!

[DavidProehl]

Oh I don't think you're wrong :) Just saying, the actuators are way nicer than the solenoids. Might as well make it a system-wide overhaul while you're in there!

That is a really good point. I've burned myself in the past by not replacing working parts that I know are prone to fail. Geez, easy to have a small project balloon in cost.

[vwdmc16]

Yay throwing money!


the light weight actuators are on my list too.

[Elvis]

That is a really good point. I've burned myself in the past by not replacing working parts that I know are prone to fail. Geez, easy to have a small project balloon in cost.


The solenoids only fail due to sticking original relays.
A $2 fuseholder with a 10A fuse solves the problem.

Updating the ECU and attaching some wires for a remote costs about $10.

[DrJeff]

The solenoids only fail due to sticking original relays.
A $2 fuseholder with a 10A fuse solves the problem.

Updating the ECU and attaching some wires for a remote costs about $10.

Elvis,

Have you got a mod outlined to add the remote locking option? I would be very interested in having a go at that. I did your door lock module fix and its been working great.

[Elvis]

Yes I have, please email/PM me privately as I have never finished it to be published.yet.

[jawn101]

Yes I have, please email/PM me privately as I have never finished it to be published.yet.

I'd love to see it too (will PM) - I did your lock controller mod very successfully already, your instructions were very easy to follow.

[DavidProehl]

It is fixed! To wrap this up:

DMCH digital lock module arrived today and fixed my remaining locking issue. Locks now work as expected.

Summary of the tips that help me diagnose it:

Apply 12v directly to solenoid, if it fires, then solenoid is good.
Apply 12v to lock wire running from solenoid to relay compartment, if it fires, wiring is good.
Open OEM lock module and manually push together the relay contacts. If one solenoid fires, there is an issue going out to the other solenoid. If none fire, it is likely the lock module (as in my case).


Sounds like some in the community will rebuild the OEM module for others (such as "Elvis" here on DMCTalk), I went with the DMCH unit to get it fixed quickly and leave the option open for a remote unlock in the future.

Thanks everyone for your assistance in helping me through this!

[jawn101]

It is fixed! To wrap this up:

DMCH digital lock module arrived today and fixed my remaining locking issue. Locks now work as expected.

Summary of the tips that help me diagnose it:

Apply 12v directly to solenoid, if it fires, then solenoid is good.
Apply 12v to lock wire running from solenoid to relay compartment, if it fires, wiring is good.
Open OEM lock module and manually push together the relay contacts. If one solenoid fires, there is an issue going out to the other solenoid. If none fire, it is likely the lock module (as in my case).


Sounds like some in the community will rebuild the OEM module for others (such as "Elvis" here on DMCTalk), I went with the DMCH unit to get it fixed quickly and leave the option open for a remote unlock in the future.

Thanks everyone for your assistance in helping me through this!

Awesome Dave! Congrats. Glad you finally got it worked out!

[jfirios]

just trying to see if the relay was bad will that drain the battery down as well.

[Elvis]

Great to hear the solenoids are not toasted and everything is working. Very unusual,
you really had luck.


But I'm wondering why it didn't work when you pushed the relay's contacts by hand
with the original ECU. Those wires and copper on the PCB are so hardcore, they can't fail.
Do you think you could take two pics for me (I bet Dave and Ron would like to see this, too)
of both sides of the ECU ? Thank you.



BTW - adding a remote is as much work as soldering 4 wires to the original ECU.


@"jfirios": yes, the original BOSCH relays go bad and stick together. That will drain your battery in
an hour !
And yes - the original ECU if still untouched - draws 13mA all the time - this will drain your battery
in 4 weeks.
And yes, it's known how to improve that for little money.

[DavidProehl]

Elvis - Below are the pictures you requested. In both pictures the failed half is the bottom half, the "lock" half of the module. The relays were not stuck at all, and both relays properly clicked on and off as the door locked and unlocked, it just didn't fire the solenoids for lock.

1242812429

[Bitsyncmaster]

Hard to see a bad connection when they don't clean the flux off the board. But like Elvis stated, it had to have a bad connection since pressing the relay did not work the good solenoids.

[Ron]

+1

Could be the contacts on the one realy...I can't see them on my monitor (shadows).

[Elvis]

Glad you guys have the same opinion.

David - thanks for the pics. As you can see on the modified pic - this is what doesn't seem to work.
the switch of the relay. As the other relay works, it can't be the fat red wire.
What remains is the relay's contacts/points, the soldering or the - two wires, two connectors.
Two bad wires and connectors are veeeery unlikely.

12438


I know you bought a new ECU and it works, but if you are curious to find out what
the problem was... I am :-)

Do you have a multimeter ? And know how to measure resistance ?

And please could you take a look at the points of the "bad" relay ? Maybe take a sharp macro picture ?

When you pressed it manually - could you hear something in the doors ? Like something trying to move ?


OR - does the new ECU always work or does it sometimes not ?
(If the inner resistance of the new ECU is better, it still might work a bit better, but I still guess tat the
solenoids are toasted like on almoste every Delorean out there with the original BOSCH relays.
This is the only time where I say the BOSCH things are worse than others.)

[DavidProehl]

Sure, below are two macro photos for you of the half in question:
1247712478

And a video of me measuring resistance as you requested:


http://www.youtube.com/watch?v=xe8ph5lKkY0

It sure looks like this should be functioning, yet it doesn't. I guess i never verified the connection between the lock module and the harness on those two wires, but it would be strange for that connection to brake without being touched.

[Ron]

12486

The circled above looks like a good candidate for a cold joint to me (dull gray). The one next to it has a weird shape (a lollipop instead of a Hershey Kiss. lol). (Maybe time to plug in the iron ;-)

The resistance looked ok, but if the plug connection checks out, I'd throw a load on it anyway...

[Elvis]

Cool, with video. Others never give a feedback at all. Thank you David :-)

But what do we see now ?
relay works manually, but it didn't work in the car ?

What exactly does it do when when you do this while it is installed in the car ?

connect it, close the doors and then listen if the solenoids in the doors do something or not
if you push the relays onf after the other.
(only if you want, but hey - it doesn't seem to be bad at all ! )

Elvis & 6548

[DavidProehl]

Yeah, it is very weird. I connect it up, move the rocker on the door, I hear the relay come to life and click as it should, but then no action in either door and no solenoid noise at all. The only thing I can think of that it still might be is that it isn't making a proper connection between the lock module and the harness on both of the solenoid wires. I know I can get a circuit through the lock module, and I know I can get a circuit from the harness to the solenoid, that must be the only thing left.

Of course having a new digital module make this all moot for me, but interesting none the less.