E30 Zone

Central locking not working on 1991 318. Thanks to some tips from you guys the pin in the connector on the a pillar has been replaced as it was corroded and broke when I removed the connector. Put in a piece of copper wire. Re soldered the thermal switch in the locking relay. Still nothing, any other suggestions. How can I check some of the wiring. I believe it is the red/black wire that I need to concentrate on. Should this have power in it a some point.

Thanks

The red/black wire at the central locking module should be live at all times. Test at the module socket by connecting a 12V lamp between the red/black and brown, and check that it lights at full brightness.
Both red/black wires should be disconnected at the door pillar socket and soldered together properly behind the speaker aperture.
The thermal fuse inside the module must NOT be re soldered using ordinary solder. To do so makes it a fire hazard, as neither the fuse in the fusebox nor the thermal fuse will protect the wiring in the case of a stalled motor.

If one of the door or boot actuators is broken that will knock out the whole system.

Now nearly working. It appears that the electrical relays that locks sticks when l lock the car. I lock the doors buy manually operating the relay and unlock them by operating the other one. When locked with key or door knob the one that locks doors sticks and the whole unit starts to over heat, obviously why the thermal switch had blown. The fuse in the fuse box had also blown. Does this sound like a new relay unit?

just go round making sure all the cables are connected. Especially the ones on the module. Give the actuators a bit of WD40 may help.