Joe Rose

OK, I give up. I've been chasing a horn problem on our '79 SC for several days now. It seems to work only when it feels like doing so. I started with the relay, but there was no problem there. I then went to the steering wheel contact--both wiper and contact ring, but this didn't help either. Then I got the bright idea of checking for a constant ground at the steeing wheel, and that's where I found the problem. With one lead of an ohm meter connected to the wheel and the other lead connected to a good body ground, I can turn the steering wheel through an arc and see changes on the meter. The resistance can vary from 0 to infinite. I thought it would be an easy fix, but for the life of me I cannot find how the splined steering shaft to which the steering wheel is bolted gets its constant ground.. On old VW's and on the 356 series there was a carbon brush located on the steering column which contacted the steering shaft and made the necessary ground contact. Later VW's used a simple short grounding strap at the rubber coupling near the steering box if my memory serves me right. How did Porsche do it on the 911? I cannont find anything in my Porsche shop manuals about this.

blutoe

What did you find with your issue ?

Kurt

Joe Rose

Hi Kurt,

I never was able to resolve the horn ground issue. Having talked with numerous Porsche "gurus" here in Charlotte to no avail I finally just gave up. Shortly after posting this issue I sold the car...complete with an intermittent horn. Sorry I can't be of any help to you.

theiceman

damn i have this EXACT issue to a T if i weave back and forth on the raod the horn cuts in and out and its not the contactor or the pickup ring. i am determined to find out how they did this.

Joe Rose

As I said, I sold my '89 with this issue because I gave up. That's not how I normally respond to an issue, and I'm still ashamed of myself for doing so. Please post what you finally find to be the cause of this grounding problem. Although I no longer have the car, I'm still very interested.

theiceman

Will do Joe, i worked on this all weekend and thought " im sure no one has seen this " then today i saw you had the same issue .. i could see the meter all over the place when i turned the wheel , and its such a simple electrical circuit.. i posted over on pelican too if you want to read just out of interest .

http://forums.pelicanparts.com/porsc...sue-horns.html

im like you and hate not knowing what the route cause is.

Joe Rose

Yup, an unresolved diagnosis is certainly nothing to be proud of. I'll check out the Pelican forum and I'll certainly look forward to your findings.

theiceman

looks like Pelican boys nailed it . and confirmed my findings ... only time meter readings are solid is when the steering lock is engaged and shaft is grounded.. its looking like a steering column grounding issue, they even have a fix.

Joe Rose

Yes, I saw their fix and it all makes sense now. Thanks for sharing with me. I guess we should call it the smuggler's box fix!

theiceman

lol yes, i just did a test run after just clamping a wire to the steering shaft then grounding it ... works absolutely perfect.. hopefully this helps someone down the road.

Obviously not a permanent fix but proof of principle.