Good evening all

I just recently ran into this issue. I had the typical issues with the power lock not fully locking/unlocking so I cleaned and greased everything this past spring. Everything was working fine. Now about 2 months ago I noticed that my lock button doesn't do anything at all. The unlock button still works and unlocks my doors just fine. I tried the button on both doors and I get the same result, silence.

Can someone point me in the right direction as to where I should be looking? I thought relay but then unlock wouldnt work either I would assume. Electrical is not my thing so I am hoping for a little guidance

Thanks in advance!

 

If you were to probe the wiring/switch with a voltmeter you would know "for sure" if the button was bad or not. Have you tried to clean all the buttons terminals with a wire brush or chemicals yet ?

Based on your description ( & without any meter testing or cleaning ) I would GUESS that the button itself was bad.

 

I will get my meter out today and try to clean the terminals as well. The thing that gets me is that both doors are doing it and Im not saying its not possible but how common is it for both lock buttons to go out at the same time?

I will update after I get my meter out and check

 

When I read this I read it as you removed the button from one side and tried it on the other side.

Ya'.... Try cleaning all the terminals on both buttons first and then re-test. You'll have a better understanding of what's goin' on once you verify that corrosion isn't causing the problem. ( MANY times power lock problems are the result of poor electrical contact @ the button or the solenoid )

 

Just for kicks I have opened one of these door lock relays in the past and found it to be actually two relays in one enclosure , set up in a "reversing switch" configuration . If you don't find anything wrong with both buttons (kinda unlikely for both to go dead together at the same time) my guess will be that one section of the relay has failed (with the other section still operable) , especially since it works in one direction but not the other .

 

Best solution for me was spraying oil into the lock solenoid itself.This freed it up better than lubing the linkage, cleaning terminals & whatever else i tried.

 

RobGuitarGod had a similar issue that he recently detailed in his thread, check it out since you might be doing the exact same thing albeit with a different button.
https://www.thirdgen.org/forums/memb...ml#post6107188

 

That is good to know. I was talking it over with my dad and agree that both dead at the same time seemed unlikely and that there must be a common connection that they share.

The relay is in the kick panel correct? I had subframe connectors installed a few months back and I wonder if when they were welded maybe it heated something up? I cant remember how close in time the subframe install was to the lock failure.

I will also check out that other thread thank you!

 

That issue was with my power mirrors. The lock circuits in our cars is pretty basic, no circuit boards just switches and a dual relay.

I actually had the same problem you're having while bench testing. Because both door connections were cut on my harness I had to reconnect them, then bench test everything to make sure it was right.

When I powered the door locks with a battery and cycled the locks, unlock worked but lock didn't. My problem was that I'd only reconnected one side of the harness, the other side was still cut off.

You'll see that the blue wire is the lock wire. Pulsing 12V on this wire will lock the doors as long as GND is on the other terminal of the lock actuators.

The blue wire appears to be wired in parallel but it's actually is series. It comes out of 1 switch into the other then into the relay. Because the other side was still cut, lock power on the blue wire wasn't reaching the relay.



The relay is in the left kick panel. Throw a meter or test light on the blue wire and hit the lock button. You should see it pulse 12v. This is where you'd connect door lock wire if you were installing a remote start.

If you have power then it could be the relay. Is it making noise? Then you could hit the motor actuator itself with power and see if it moves. Power on 1 pin, GND on the other and it should move. Swap polarity to move it on the opposite direction (lock or unlock depending on which polarity causes which).

You can access the actuators wires with at the relay.

Power to the switch and relay (ORG and ORG/BLK) isn't your problem because unlock wouldn't work without them both.

 

Sorry for not following up, my issue ended up being a ground problem. I pulled the kick panel and unbolted the relay only to see that none of the locks worked so it got me thinking about the ground. Cleaned it all up and added a little dielectric grease and she was good!

 

For my own peace of mind, on my 87 Iroc, I added an extra ground wire from the relay mounting bolt to one of the obvious grounds under the dash. In theory it shouldn't need it, but I figured the lock circuit could use all the help I could give it.

GM used two different relays in thirdgens. The early cars used the big metal can that grounds through it's mounting bolt, while the later cars have a plastic relay with an extra wire for the ground.