Central Locking issue

PopsRacer · 11:08 AM

Hi,

1988 Carrera coupe.

I have been pouring over the old threads here about central locking. Yesterday mine got wonky.

* I can't lock the car with the key from either door. From the DS side the lock goes down and then pop back up. The PS side barely moves. Same behavior if I use the key in the Pass door.
* if I am sitting in the car with the doors closed, I can lock both doors with the center console button and the PS door pin does go up and down normally.

Given those two things, I think I am leaning towards a micro-switch being bad (or perhaps the cabling/plug?) but I am not clear on how to test to see which side is the issue without taking at least one door apart.
The passenger door is not moving the lock "pin" properly & gets used a lot less, so maybe it's the issue?

Then again the car had some kind of repair in the past on the drivers door. (you can tell from the paint in the jam/a-pillar area) so perhaps the drivers side got dirt in there? Then again it seems to work fine otherwise.

The factory manual looks for 12V to the controller and a good fuse & then jumps right into replacing the micro switches, as does the Bentley. Is the gist that we open one door, test and then open the other if we have chosen poorly?
Do we really have to guess? lol. TIA!

A930Rocket · 01-06-2025, 06:34 PM

No answers for you, but I’m interested in this. My passenger side door will unlock with the key in the doors and the central button, but will not lock. Same thing if I use my remote.

GH85Carrera · GH85Carrera's Garage

So if you are in the car with doors firmly closed, it will lock. Both doors must be fully and tightly closed. Turn the key in either door and it is supposed to lock.

If not, yep, you have a micro switch maladjustment or bad micro switch. I am surprised you can get the doors to lock at all with that problem in the micro switches.

carreradpt · carreradpt's Garage

Had the same thing happen. It was a microswitch.

PopsRacer · 01-08-2025, 06:18 AM

Thanks, all. I think I will pull the PS door apart since that is the one where the lock "pin" (*whatever the little thing is that pops up and down) does not move properly and go from there. Now I just need slightly warmer weather... will report back

GH85Carrera - my thought on the 'why' it still locks from inside is that the switches are both in 'neutral' - door closed, no key turning stuff - so the switch issue isn't interfering? icbw.

PopsRacer · 01-26-2025, 04:10 PM

It finally warmed up enough to dig into it. I was able to test both doors from the header plug to the controller for continuity (and they seem ok) but the controller board has a nifty crack in it. I think it got whacked at some point in the past. Photos, schematics and whatnot here if helpful: https://www.joepampel.com/post/central-locking-issues

A930Rocket · 01-26-2025, 07:21 PM

Wow! Nice write up Pops!

PopsRacer · 02-21-2025, 09:17 AM

quick update - I had some errors to the blog post - so I fixed those (sorry!) and I added some more info. I had microswitch connections to the header plug wrong (it’s 5 to 7 & 5 to 9) bc I got confused on the drawing. it happens.

Still don’t have it working. Would go faster if I didn’t have to work, lol and if it wasn’t single degree cold out there.