Auto Door Lock System Problem

icemann427 · 10-13-2015, 07:12 AM

About two weeks ago, the passenger door of my 87’ 930 failed to lock when I hit the lock button on my Viper alarm remote. The driver’s door locked, however. This scenario went on until this past weekend, when now, the driver’s door does not lock, either. When I touch the lock button, I do not hear any noise from either door lock actuator (however, I do hear a click in one of the alarm boxes). However, when I touch the unlock button, I can clearly hear both actuators make an attempt to unlock the doors even though they are already unlocked.

I took the car to a local alarm/stereo retail store who installed the alarm about 15 years ago. He showed me the alarm is working, perfectly, and showed me the “unlock” wire going into the alarm is “hot” while the “lock” wire is dead. He said the problem could be anything from a relay, bad actuators, to a few other things. Before letting him loose and spending a lot of money having him attempt to fully troubleshoot the problem, I told him I would ask the brain trust on this forum if they could assist and give me/him some direction.

Anyone experience anything similar to this? Any help would be greatly appreciated.

JFairman · 10-13-2015, 07:49 AM

If that after market alarm system is 15 years old your better off removing it and installing a new one. Or go back to just the stock system.
Paying someone to try and fix it is probably a big waste of money.

icemann427 · 10-13-2015, 08:01 AM

Thanks, Jim. Yea, I hear you, but the alarm works, perfectly, and isn't affecting the stock system. Just something in the factory system, somewhere. I just find it odd that the system will attempt to unlock but it won't lock. No juice for locking. I looked at a bunch of previous threads and nothing like my problem.

JFairman · 10-13-2015, 08:25 AM

The black plastic factory alarm system control box is under the front wind sheild cowl nearby the glove box. Maybe it has a headache or maybe it's not there anymore.

The door lock actuators seem pretty solidly made and last a long time but you never know how they're doing or how the wire harness going to them is doing after many years. It gets flexed around a little every time you open and close the door.

rsrfan · 10-13-2015, 09:22 AM

I had this problem
Years ago. The plastic links which attach to the solonoids break and were superseded with a new design. Search under my username and central locking in the 911 technical forums for a detailed explanation

rsrfan · 10-13-2015, 09:33 AM

I bumped the thread on the 911 technical
Forum. It's titled " part # help"

icemann427 · 10-13-2015, 10:27 AM

Wow, thank you so much guys!! And especially to you rsrfan!

icemann427 · 10-13-2015, 02:58 PM

I have the passenger door panel ready to take off except the 2.5" diameter plastic ring around the manual door lock turn knob isn't allowing the panel to come off. Can somebody please tell me how it comes off? I don't know if it just comes off with force or some other way...I just don't want to break it. Thank you!

dap930 · dap930's Garage

Pry out the center button in the round knob. That uncovers a screw to remove the knob. Once the knob is gone, the plastic ring comes right off.

icemann427 · 10-13-2015, 06:08 PM

Did all of the above but my outer ring just doesn't want to come off. Since your's came right off, I guess there isn't any magic to it then. I guess I'll try a little more force, then. Just didn't want to break something if there was some small mystery procedure in taking it off. Thank you!

JFairman · 10-13-2015, 06:43 PM

The plastic ring screws off counter clockwise after you remove the plastic knob as described above. Usually you can get a good grip on it with your thumps to screw it off. It's plastic so it's not screwed on tight.

If you can see a couple holes or slots in it down by the threads you can stick the pins of some snap ring pliers into them to get a more solid grip on it to screw it off.

When reinstalling it a little vasaline on the threads could lubricate the plastic threads so it doesn't get stuck again. Just don't screw it on too tight.

icemann427 · 10-13-2015, 07:00 PM

Thanks, Jim. As always, you da man!

icemann427 · 05:41 AM

I took both door panels off, this morning, and found out both actuators work AND that the ball end of the passenger actuator had failed. I played with the system in both doors and found that if I grounded the right male end of the connector that mates to the connector that goes to the door key lock, the actuators would unlock (picture of that connector is in the post, below, since I forgot to include it in this post). I also found out that if I touch the right and left male ends, together, of the same connector, the actuators lock. AND, not only do they lock, they attempt to keep themselves in the locked position even when I pull on the arms to attempt to pull them into the unlock or released position.

I still was not able to get the system to lock using my fob or the door key (they will unlock with the fob and door keys).

With that little extra tidbit of information, does anybody have any more ideas?

Thank you very much!

icemann427 · 10-14-2015, 12:57 PM

Picture from above post.

icemann427 · 10-20-2015, 02:45 PM

Found out the connector I'm holding in my hand, pictured above, had a bad connection (one of the places Jim [JFairman]said there may be problems). Took a few hours to troubleshoot it, but it is done...

Thank you, all!

icemann427 · 10-21-2015, 07:41 AM

FYI, everybody, if your white ball connector fails/breaks where the door actuator rod meets the door handle lock mechanism, you can just buy the black ball connector meant for the automatic heat rod located between the seats. It is much easier to do this replacement instead of buying the new plastic rod and replacing the stock metal rod with it...