Assessing OEM Door Lock Module (DLM) and solenoids

[DMC-81]

Hi there,

As part of the refurb of my doors, can you all help me assess my DLM and solenoids? When I bought the car, the central locking system was unplugged, as most of them are. I haven't attempted to plug it in yet as in want to assess the system first. I removed the DLM and one solenoid today (passenger). I opened the DLM and (separately) tested the solenoid with 12V and it works in both directions. I can move the plunger freely... It's kind of springy. I have yet to test the driver one.

Both units appear not to have the burn signs that I read about. Here are some pics. Can you take a look and see if you notice anything awry?

image.jpg image.jpg image.jpg image.jpg image.jpg

Assuming that everything is OK, I want to keep the original system as long as possible. However, I understand that the DLM has a flaw. I intend to install an inline 10A fuse in it to protect the solenoids, and adjust the latches and locks per spec. Is there anything else I should do? Replace the 2 relays, etc?

Thanks for your opinions.

[sdg3205]

I wrestled with an original DLM for a long time on a project car. I'd get intermittent lock or unlock, can't recall. In the end i bought new relays from DMCNW. Problem solved. New relays are about $12 and can be soldered into place quite easily.

IIRC, original DLM's would burn out solenoids by a relay sticking. Fusing the DLM will tell you a lot about your situation. I kept blowing 10 amp fuses, so I knew something wasn't right.

[PJ Grady Inc.]

You can't see the points on the relays in the pics but you are probably a candidate for reconditioning these parts to a better than NOS standard which I strongly prefer over aftermarket actuators. We offer better reconditioned modules and solenoids on an exchange basis. If anyone is interested please PM me.
Rob

[DMC-81]

Thanks Dave and Rob. Here are close up shots of the relay points:

image.jpg image.jpg

If that's what wears/sticks/fuses they seem pretty OK. That gives me hope about the condition of the Driver Soleniod.

I may change the relays if the new ones are an improvement.

Question: Whether I change the relays or not, will the inline fuse protect me ( in theory) of the solenoids burning out from relay failure? I'm not anxious to get locked in the car.

Thanks again.

[David T]

Thanks Dave and Rob. Here are close up shots of the relay points:

image.jpg image.jpg

If that's what wears/sticks/fuses they seem pretty OK. That gives me hope about the condition of the Driver Soleniod.

I may change the relays if the new ones are an improvement.

Question: Whether I change the relays or not, will the inline fuse protect me ( in theory) of the solenoids burning out from relay failure? I'm not anxious to get locked in the car.

Thanks again.

The short answer is YES. If you use the OEM door lock module and anything goes wrong the 10A in-line fuse will blow rendering the door lock module inoperative. You will be able to lock and unlock, open, and close the doors manually. This advice is for everyone still using the OEM DLM. Either cut a 10A in-line fuse into the big red wire or disconnect the big red wire from the circuit breaker.

[opethmike]

Honestly, just get one of the new door lock modules. Work real nice and don't have the frequent problems of the stock units.

[David T]

Honestly, just get one of the new door lock modules. Work real nice and don't have the frequent problems of the stock units.

A better door lock module will solve many of the problems but not all. You still have to have both doors properly adjusted and the solenoids can't be bad. Some owners just don't want to spend the money to get the better DLM so adding the fuse is a cheap work-around.

[opethmike]

A better door lock module will solve many of the problems but not all. You still have to have both doors properly adjusted and the solenoids can't be bad. Some owners just don't want to spend the money to get the better DLM so adding the fuse is a cheap work-around.

Guru,

I didn't say that the new DLM would solve all of the problem, I said it would solve the problems around the stock DLM.

[PJ Grady Inc.]

Guru,

I didn't say that the new DLM would solve all of the problem, I said it would solve the problems around the stock DLM.

Not really Mike as I've seen a lot of failures with the new modules. They also have about a one second delay before activating the solenoids which I can't get my head around. (No jokes there Miky boy...control yourself!). I think the best fix for now is rebuilding the originals with better relays until Lockzilla's become available again. Wait did I just jinx myself or will the mighty "Zilla" soon return to save the Delorean world from electrical Armageddon? I guess we'll just have to wait and see!
Rob

[Bitsyncmaster]

The design problem with the OEM and original LockZilla was the way they created the time delay for solenoid operation. Both designs used a 1000 uf. capacitor that powered the relay coil. That results in the relay coil voltage slowly dropping which caused the relay contacts to also open slowly and burn the contacts. The LockZilla used 70 amp relays so its contacts may last longer.