Hi all,
Recently picked up a 9/92 build 525i touring and it's in pretty good shape apart from a few niggles - the main one being that the central locking doesn't work!
Things I've tried (not including a lot of Googling):
-New general module
-New relay module
-Checked all fuses with multi-meter (only one blown - which was for the aux fan)
-Checked fusible link
-Powered actuators directly through the door loom while unplugged from the body loom, actuators react when powered on the correct pins
Interior lights and electric windows work perfectly! When you trigger the central locking using the drivers side pin, door barrel or boot lock, the RM clicks, but no locks operate. Not even the fuel cap lock
What would cause there to be no power getting to the actuators? Should I start pulling fuse boxes out to check for any bad connections and corrosion? Everything looks very clean under the back seat without any signs of water damage or misuse. Could there be another relay I haven't identified?
Appreciate any guidance.
Check the two trigger wires behind the left front speaker. You should see a brief 12 volts signal on the lock or unlock wire when you lock or unlock. Depending on your results, you can move forward or backwards from there.
demet
None actuate at all? That is odd.
One possible source of issues would be the splices under the rear seat and carpet, especially if your car had a leaky heater core that leaked into the interior at some point. On my Touring, the driver front door wasn't getting power to any of the central locking bits, and the culprit was the X481 splice under the rear carpet on the driver's side of the trans tunnel. Could conceivably cause failure for all central locking power feeds depending on how it failed. Pictures can be found in my build thread here: https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/1993-525i-touring-impulse-build/123652/page3/
+1
Scroll down in this post for a few pictures of what you are looking for:
https://www.bimmerforums.com/forum/s...2#post29161852
Thanks guys, time to start tracing wires it seems!
It is strange that none of the actuators in the entire system work, but the relay module still clicks along. I'll keep this thread updated with any progress.
Can the door lock actuators be simply disconnected at the mechanical link, and the door locks operated by old-fashioned turning of the key in each lock or pushing/pulling each knob?
They all lock and unlock perfectly fine manually. This has been put on the back-burner until I have a spare weekend to throw at it, so no progress yet.
Wiring gremlins re. door locks, etc.:
I removed the black plastic sheath over the wire loom which attaches to the left side trunk lid hinge, and found that of 15 wires, 8 had worn through the insulation, and two were completely broken. The broken wires were the blue/yellow and the brown (ground?) wire. Reattached/reconnected these broken wires in hopes the central door lock systems would work, but found no change whatever... So, there's another fault(s) somewhere else.
From this, I recommend starting your diagnosis and repairs with the trunk hinge loom.
Checked the tailgate wiring and only found one broken wire which was repaired... Which let me open the tailgate glass - but unfortunately no change in the central locking.
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