After R&R of the instrument pod to replace the ignition switch and messing around checking my stereo wiring in the center console, I found that my central locking function is not working after I put it all back together.

The specific symptoms are:

• Locking/unlocking with key from driver's door only locks/unlocks driver's door
• Locking/unlocking with key from passenger's door only locks/unlocks passenger's door
• Unlocking one side deactivates alarm on that side's door only - the alarm system stays active and blinking on other door whether locked or unlocked
• Central lock button is lit, but does not lock/unlock either door

I am pretty close to 100% sure that I must have undone a wire running to the central lock button, but I don't know what to look for (and don't want to waste 2 hours trying to figure it all out), so I am posting this thread to get some direction on where to start troubleshooting.

If you are familiar with this system and have an idea of what might be wrong, please let me know what your guess is. Thanks!!!

 

On my '86.5 the plugs for central locking, a/c, warning switch are on the passenger side behind center consul side cover. If you were moving things for the stereo wiring it is possible these 2 plugs were affected. The control unit itself is on the other side and is usually the first thing you see when driver side cover removed. My interior lock was sporatic and turned out the control unit was bad (driver side) As I have disassembled the consul a few times I also realised the femal end of plugs had warbled out a bit not allowing good contact when put together. Not sure if this will help, just what I have found.

 

i have the same problem so i'm listening too.

Mads

 

consider the red key button above the radio - it has frail wires.

 

Thanks guys - I will check out the wiring to the central lock button this weekend. I'll let you know what I find under there.

 

UPDATE: No dice.

I located both the central locking controller (911 618 113 01) under the console on the passenger side and the alarm relay (928 637 160 00) on the driver's side. I poked and prodded at all of the wires and connectors, pulled and replaced the alarm relay, checked the soldered wires on the back of the console insert (the one with the central lock button on it), and found nothing wrong anywhere.

But it still doesn't work - same symptoms as described in the original post.

A used central locking controller is $230 at 928intl.com, so I'm not going to buy one of those just to see what happens if I replace it.

Is anyone familiar enough with how the central lock and alarm systems work together to suggest anything a little more focused than poking and prodding?

 

I have a good lock unit if you end up needing one.

 

check the fuses in the panel and the 2 fuse holders over the CE panel they are both red wires probably a blown fuse

 

Yes - check the fuses first

Alan

 

I have no advice, I just enjoy scrolling the screen and seeing your avatar roll by.

 

I have centre console out now (replacing temp sensor fan motor) and I discovered the 6 pin connector to the central locking switch was not connected. It's on right hand side about level with passenger knee, and was curled up with wiring looms so hard to spot till I disentangled these.

There's a photo of it in this thread which I posted when i struggled to identify it. Shows wiring coeds so will be easy to confirm whether or not yours is connected before you suspect alarm/locking control unit:

https://rennlist.com/forums/928-foru...ight=connector

 

Duh - now why the hell didn't I think to do that??? OK, will check fuse #1 at lunch and get back to yous guys later.

Heinrich, thank you so much! We'll see how things go. If poorly, would you be willing to let me borrow it for diagnostic purposes, then buy it from you if it cures my ills?

Orest, thanks for the compliment. But Larissa discovered my little lady last night while I was reading this thread and poking under the console and got a little jealous. Uh-oh!! But she did admit that that's one hot ***!

Now pay up for a Rennlist membership already, you cheap bastard!! Did you rebuild your engine all by yourself or did you get a little bit of help here?? Isn't that worth a few bucks? OK, for castigating you in public like this, I'll get us shots at the next wedding or deb...

 

Double Duh!!

I went to check the fuse in slot #1 and found that THERE WAS NO FUSE AT ALL!! Where the hell did that thing go??

This is a bit of a mystery... I pulled the interior lighting and instrument panel fuses (#7 & #10) when I was taking apart the dash for the ignition switch replacement, but I didn't think I pulled #1 (why would I after all?!). Whatevs - a mystery it may be, but fascinating it ain't, so I'm just going to move on.

Thanks for the suggestion to check the fuse, everyone! This case is closed...

 

before you go please get a fuse relay chart here
www. 928gt.com find page 2 and then tips and links print one off

Reason being is that some of the fuse slots should be empty on different years, so filling the slots could cause other problems or shorts

 

I have my original fuse chart from the manual, Mrmerlin. My #45 is supposed to be empty, but #1 (central locking) is not supposed to be. You may have misunderstood me - I mentioned that I pulled #7 and #10 when I was replacing the ignition switch (and later replaced them), but I do not recall pulling fuse #1, and had no reason to. Nevertheless, it was missing...