92 535I Steering column ground

[surge82x]

Ok, I have, what I would consider, a strange question. I'm working out some of the gremlins in the electrical system on my new acquired E34. It is a 92 535i, built 02/92. After a lot of searching on the forums, realoem and google I can't seem to find anything that points to the answer. I'm probably not searching for the right terms so forgive me if this has been covered **-teen times here. I'm new to the E34 realm.

The horn doesn't work and I have some strange behavior from some of the stalks at no specific frequency. Not sure if they are related but here is the research, testing and conclusion I've come to.
There is ground on the housing for the steering column, but none on the actual steering wheel hub or the steering shaft it's self. I've attempted to link the steering shafts together across the rubber dampener, but no luck there. With a continuity tester, I've tested for ground all over the steering shaft, center hub and else where with no luck unless I press the horn button. The link between the horn button and relay exist, but not between the center hub/wheel and body ground. I'm trying to find out where the common, or specific ground goes for the steering wheel and horn?

I'm assuming it's something easy, that was either pulled off when the PO had the engine rebuilt or the po him self screwed up with the rest of the bad wiring jobs in the car.

TIA

[attack eagle]

that would be because there is no need for a ground on the shaft. As you saw it is joined to a rag coupler, so it really isn;t grounded to anything.

did you pull up the ETM and trace out the circuit for the horn?

[surge82x]

I've looked at the ETM and the horn circuit specifically. The ground is only defined as 31, which isn't referenced anywhere else that I can find in the ETM. Beyond that definition there is no mention in the component location area or the connector area for a horn/horn switch ground that I could find either.

Since I had no clue on the actual location of the ground, that was one point I knew some manufacturers used for a common ground for the horn switch and column housing.

[attack eagle]

look at one of the steering wheel swap threads. Might be a clue there.

your testing though seems to indicate the horn button itself is fine (horns are often ground switched). Did you test for power at the horn itself? Any fusing (been too long and i don't have my supporting documents anymore) that could be at fault?

[surge82x]

I'll check that out. Yes the horns them self work fine, if I supply ground to the switch leg on the relay that normally is supplied by the press of the horn than you have that sweet bavarian sound.

I'll check out the swap threads, thanks for the advice on that.

[davloh]

I'm having the same problem with my horn. I can't find how the main center section of the wheel is grounded. I would have thought the column itself would be grounded somehow.