Central Locking System

I'm not getting any action out of the central locking system. When I turn the key in the socket on either door, I can hear the relay (next to the central locking module) click, but no action at the lock mechanisms. The driver door solenoid had seized up, so I replaced it. I'm wondering whether the seized solenoid fried the central locking module. Has anybody had experience with central locking system? Any thoughts?

Andy
1987 325ic

Hi Andy,

The central locking system can be a fickle thing.

The first place to look is the connector on the front driver side door post. Pull back the rubber 'boot'; then with needle nose pliers or similar, pull the white plastic plug with the wires from it's socket.
You will likely find a lot of corrosion and possibly even broken or missing pins. I nothing is broken, you can clean the contacts with electrical contact cleaner then push the plug back in. Most times, this takes care of any issues with the central locking system.

If all of that turns out to be ok and the problem persists, then further investigation will be needed. The simplest diagnostic for the Central Locking module is to try a known good working one in it's place.

Let us know what you find and if things haven't improved, one of our Central lock gurus might be able to help out

There is a fusible link type element on the control card. Check the archive on the wayback machine and there you will find an article with pictures of the repair.

Bob in Lake Havasu

A while back my locks stopped working but I could still hear them trying to lock, the buttons just weren't going down. I sprayed this stuff I use in the shop down the shank of the button rod, soaking whatever is down there and then I sprayed it in all the places I could get to with the door panel on (you'd be surprised how many places there are) and they started working fine. In fact, two years later they're still working nicely.

The stuff I use is "corrosion block", I get it at Napa. It's a marine thing that works great on stuff, especially things that are hard to get at.

Not saying it will fix yours but it did wonders for mine

Thanks for your inputs. It turned out that it was the fusible link on the card. I suppose when the solenoid siezed, it caused that to melt down. It's a pain to get to, but a pretty easy fix once you know what to do. I haven't taken apart the door solenoid to see what happened to it. It is actually the second one of these to go; I had the same issue wth the passenger side last year. It just froze up, and even after removing it from the car, I can not force the slide to move. I may cut into it just for grins to see what is going on. Meanwhile, a used replacement was readily available on eBay.

For those of you in the USA, happy Independence Day. I sometimes wonder if years from now, some of our middle eastern and north African friends will be celebrating an Independence Day that ocurred in 2011.

Andy
1987 325ic

How much trouble was the card to remove from the car? I have wanted to inspect mine for a incorrect connection resulting from an after market alarm installation now that the alarm does not work....

Bob in Lake Havasu

It was not as difficult as I initially imagined; I suppose the entire removal process took 20 minutes. You have to remove (in order) the left door sill (3 or 4 push rivets), the hood release handle (two screws), the left front kick panel (one screw), the left front speaker (three screws) , then the bracket that holds the module (two screws) and slide out the assembly. Once you unplug the module, you can pop off the bottom (the end opposite the pin connections) with a knife blade, and the board slides right out. Somewhere I read a caution to not unplug the module unless the battery is disconnected, so if you have to open the hood, do so before removing the hood release handle. Good luck.

Andy
1987 325ic



Edited 1 time(s). Last edit at 07/06/2011 01:09PM by akstraw.

Quote
akstraw
so if you have to open the hood, do so before removing the hood release handle. Good luck.

Or pull the cable, or put the large screw driver through the well known location at the front.