So. Central Locking Doesnt work, mistery ? any help

Post Sat Mar 23, 2013 7:58 pm

Done the red and black modification. No joy,

Check the relay and the bit that the solder normally breaks away was broken. Therefore I resoldered and the locks opened. However connect back up, still no central locking. ANd there is now smoke coming from the relay where I soldered the part. And that metal strip is roasting hot.

Any ideas guys ?..

Post Sat Mar 23, 2013 8:06 pm

Did you add more solder when you fixed the broken link? If you did, you've probably buggered things up even more now.

Post Sat Mar 23, 2013 8:31 pm

It's a special solder in the relay and if you added too much or changed it for something which flows more current which the heat and smoke points to then chances are you've over done it. If you're lucky a new relay may sort you out.

What I did was take the wire out of a low current fuse and solder that in the gap, my thinking being that if there was a current surge the original design would still work and protect the system.

Post Sat Mar 23, 2013 8:46 pm

aww damn.. I pressumed standard solder would solve the problem. The relay still seems to be working tho ? I was concerned about the smoke and turned it off. I didnt realise it was a specific solder. Are the relays not really expensive ?.. I still dont think its the relay and this ''red & black trick' was the best solution... Its frustrating if anything. Another thing that is weird in some threads they say that the unit and relay is in the same place however mines is the same as this relay and a plug that looks unplugged :-

http://www.google.co.uk/search?hl=en&q= ... 1136%3B852

Post Sat Mar 23, 2013 9:13 pm

It depends which version you have, mine is an 1988 and I have the silver relay under the dash which is usually the one that is resoldered..... From the picture it looks lik you have the control unit?? What exactly did you solder? any pics

Post Sat Mar 23, 2013 9:24 pm

The thing that you've bodged up in the locking ECU is a thermal fuse, which was/had done the job it was designed to do - protecting your car from bursting into flames and burning to a crisp.
The thermal fuse had tripped because there's a short in the locking wiring, or, more likely, one or more shorted out lock motors.

Post Sat Mar 23, 2013 9:57 pm

okay.thanks guys. so brian ur not suppose to.resolder that thermal.fuse. tho when i made contact woth it its opened the locks so i pressume that is the fault. what would u.suggest? thanks

Post Sat Mar 23, 2013 9:58 pm

A new replacement C/L ecu now.

Post Sat Mar 23, 2013 10:12 pm

the ecu/ relay is still working though. ile just need to remove the solder? is that thermal trip.suppose to be undone

Post Sat Mar 23, 2013 10:13 pm

If the locks opened the instant you remade contact across the thermal fuse, without an "unlock request" signal from anywhere, then it sounds like the ECU is powering the lock motors continuously, instead of just a short pulse. The unlock relay on the circuit board should just pull in for half a second, then release.
If the above is the problem, then the ECU has probably been damaged by water, and a fresh one is required. hopefully the lock motors have survived, but there's no guarantee.

Post Sat Mar 23, 2013 10:13 pm

How will you "Only" remove the new solder?