Central Locking Question!

[veedubdude]

Came out to the car as normal today , to find the central locking has packed up! I can open the drivers door with the key, but cant lock it with they key, it only locks half way; which means the handle can still be pulled opening the door slightly - but not enough to get in.

Whenever it tries to operate I can hear a grinding/screeching noise coming from down by the accelerator pedal! Before I get a chance to strip it down and see what is causing this, does anyone have any idea what it'll be so I can get the parts sourced?

My first guess is a central locking pump, but Im not sure i E30s have them?? You'll have to excuse me, I know zippo about how CL works! Ive searched and read about the CL electric module below the drivers side speaker, but assumed if Im hearing something trying to move it doesn't sound like a CL circuitboard?

Cheers, Andy

[Chris36]

Had this - did the red/black wire disconnect thing - this didn't help - However I found that the fault was the C/Locking ECU had a damaged resistor. I soldered it together & its fine now. Had exactly the same symptons as you. Had to manually close all doors. But could open the drivers door ok!! You will find the fix if you use the search button.

[veedubdude]

Thanks, Ill have a search about the resistor thing! Did yours make a whirringish noise when it was trying to do the central locking when this happened?

[Rav335uk]

If you need a rplacement cenral locking ecu i have one.

[blackcountrybimmerman]

The c/l ecu sounds like the game "operation" when it's fubar'd.

You can either solder the "thermal fuse" inside the ecu, or replace it.

I would also check the door harness for breaks in the cables in the rubber bit between the door and the lower "A" post.

Also look for the red/black wire mod on here using the search facility.

[Rav335uk]

if you decide to solder it, you can't use normal solder,you have to use a lower temp one iirc

[blackcountrybimmerman]

I'm not sure on the lower temp solder Rav, I found that there was plenty of solder already there on the "thermal fuse" to make a temporary repair.

[Brianmoooore]

if you decide to solder it, you can't use normal solder,you have to use a lower temp one iirc

Quite correct!
The reason the lock won't work manually is wear in the L shaped alloy piece on the back of the lock barrel. With working central locking, once the mechanism has moved partway, the lock motor takes over and finishes the job.
If the thermal fuse in the locking ECU has failed, then it won't make any noise at all, as it will be totaly dead.
Do the 'red/black wire' modification, as I've posted on here many times.

[Alex]

dont suppose anyone has a pic of the thermal fuse , its happend a few times to me, where by it makes a funny noise rather than lock, although i just lock and unlock it a few times and its back to normal

is low temp solder expensive ???