hypo

Hi guys,
I have a hard to work out electrical issue on the automatic steering column my 1990 r129. the motor is working ok but not through the switch. also the electric mirrors dont work. its not the plastic dogbone or cog - its a wiring issue (i think). Theres no power at all getting to any of the wires at the up/down/in/out switch plug.

so to test the column motor I ran a positive feed from under the bonnet to the connector leading up to the switch.

it was at this point i had some joy.
all the wires apart from the black (as its the ground) gave results but still not good enough:

hooking a positive to the:
GREY wire gave me up+down+out (but shorted out when pressing the in function).
RED wire gave up+down+in (but shorted with out)
BLUE wire gave in+out+up (but shorted with down)
GREEN wire gave in+out+down (but shorted with up)

hooking up any of these wires too the positive also gets the outside mirrors to work.

Ive done some searching online but cant find a location for a relay and as for a control module all i could find was that it was meant to be behind the passenger kick panel (looked but there was nothing there).

this is a real hassle-I really hope someone can point me into the right direction.

vitruvius

I had similar problems and they were due to either under voltage (fix by charging your battery fully) and/or module failure. Used and tested modules are available on eBay but they are about as old as yours so may fail soon. The module is relatively easy to access by pulling up the carpet, cushioning, and a large plastic cover at the front (firewall) of the passenger footwell. It's the one highest up with the connector at the top - above a sound system amp or module.
I knew I had mine fixed when the side mirror was warm - I didn't know that was a feature.