Assessing OEM Door Lock Module (DLM) and solenoids

[DMC-81]

Good job, but the water didn't do anything to the coils.

The reason is and stays the relays.
Especially the original BOSCH relays - they stick together because of the high current and not so good driving circuit.

With the replacements I use I have not had any problems anymore.

Just checking in on this OEM door lock modification and refurbishment thread. Can't believe it's been almost 7 years, but I'm happy to report that the system has worked flawlessly ever since.

Also, I didn't see this last post, so I'll respond for posterity:

Actually, in my case it was indeed water intrusion that caused the burning in the solenoid. I know this because there was evidence by way of water staining in the inside bottom of the cylinder case where water pooled, and a trace where the water came in through the case seam. In addition, my relays were in pristine condition and passed testing, so much so that I saved them as spares.

Over the years since I did this project, the car was caught in torrential Florida rain a few times, and thankfully the silicone RTV seam I added prevented a recurrence.

[mhanch]

Digging up an old thread -

I just did the Resistors and Transistors on my lock module (Relays look really good. )

and the issue I am having is that only the Lock sire works properly. If i put power tom the Unlock side, it doesn't want to fire. Once in a while if I tap it repeatedly it fires, but then won't fire again for several tries.

Any ideas? i'm using 1/4 Watt resistors, and the Transistors from Elvis' doc.

[Bitsyncmaster]

Digging up an old thread -

I just did the Resistors and Transistors on my lock module (Relays look really good. )

and the issue I am having is that only the Lock sire works properly. If i put power tom the Unlock side, it doesn't want to fire. Once in a while if I tap it repeatedly it fires, but then won't fire again for several tries.

Any ideas? i'm using 1/4 Watt resistors, and the Transistors from Elvis' doc.

Probably your switches in the doors need adjustment. Those are the switches that tell DLM if doors are locked or not.

[mhanch]

I?m testing on the bench. Module worked fine in the car before the update. Wondering if maybe one of the new components could be bad out of the box?


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[Elvis]

Just checking in on this OEM door lock modification and refurbishment thread. Can't believe it's been almost 7 years, but I'm happy to report that the system has worked flawlessly ever since.

Also, I didn't see this last post, so I'll respond for posterity:

Actually, in my case it was indeed water intrusion that caused the burning in the solenoid. I know this because there was evidence by way of water staining in the inside bottom of the cylinder case where water pooled, and a trace where the water came in through the case seam. In addition, my relays were in pristine condition and passed testing, so much so that I saved them as spares.

Over the years since I did this project, the car was caught in torrential Florida rain a few times, and thankfully the silicone RTV seam I added prevented a recurrence.

I say it was not the water, but hey - it works fine now.

The original relays are not good, the material of the points is not good.
The replacement relays that I use have a better point material, never had to replace
them even after almost 20 years in my car and many updated modules.

[Elvis]

I?m testing on the bench. Module worked fine in the car before the update. Wondering if maybe one of the new components could be bad out of the box?


Sent from my iPhone using Tapatalk

Did you replace the relays ?
The replacements I suggest sometimes touch the plastic housing an won't switch correctly.
Try it without the housing if it works fine. If yes - I have a suggestion / solution.

[DMC-81]

I say it was not the water, but hey - it works fine now.

The original relays are not good, the material of the points is not good.
The replacement relays that I use have a better point material, never had to replace
them even after almost 20 years in my car and many updated modules.

It's OK. We can agree to disagree. As I posted, there was evidence of water intrusion in both solenoids and the resulting shorting in the bottom portions of the magnet coils in the area where the water pooled. In contrast, the original relays tested just fine. I even kept them as spares.

I'm sure there are DLMs where the relays failed, but mine wasn't one of them

[David T]

While it is possible for the solenoids to be damaged by water, that is not how most of them get damaged. Most get damaged when the contacts on the relays get welded together and too much current goes through the solenoids for too long shorting the windings in the solenoids. The contacts get welded together because the relays are not designed to carry that much current and nothing was included in the design to prevent arcing when the circuit is opened. Over time the arcing causes the contacts to weld themselves together. As for water damage, the holes in the bottom edge of the doors have to get plugged up and the door fills with water. That's a LOT of water! I have seen that on cars that were left outside for a LONG time, not cars that get used. Once you open the door all that water will run out.

[mhanch]

Did you replace the relays ?
The replacements I suggest sometimes touch the plastic housing an won't switch correctly.
Try it without the housing if it works fine. If yes - I have a suggestion / solution.

I eventually got one of Dave's units to replace the whole thing - but thanks for asking!