Horn button ground via steering shaft

[Roberts440]

Hello all, my first post here.  This might be a really stupid issue, but I've traced my horn problem to the fact that my steering shaft is not grounded.  A curious quirk is that it works if the ignition is off, allowing the shaft lock lever to drop onto the lock plate, thus providing a ground to the shaft.  Apparently, the bearings and lower shaft coupling are providing unwanted or unexpected electrical isolation.  I can't find any other way that the shaft could expected to be grounded.  I could attach a flexible wire from ground to somewhere on the steering shaft to fix this, but I do wonder if I'm just missing something.

Thanks in advance

[Dakota]

There are no stupid questions here, otherwise I would've been banned from future posts years ago.

Best I understand it, your steering shaft would normally (at a minimum) be grounded through the 4 mounting bolts that support it.  Many many posts here point to bad grounds as one of the major causes of electrical issues.   If I recall correctly, there's a ground strap shown in the 70 Challenger service manual running from one of these mounting bolts to the dash frame, but many/most cars don't actually have them.   There's one eBay right now, as shown in the link below.   I made mine.

I ran supplemental grounds all over my car:  separate ground for the fuel pump, extra ground for the dash frame, dedicated ground for the taillights, etc etc.   For my 2 cents, it's one of the best wiring moves you can make short of replacing your aged harnesses.

https://www.ebay.com/itm/225186766666

[dodj]

Did you rebuild the shaft by any chance? It's been a few years since I've had mine apart..ok, a LOT of years..lol...but there is a plate over the bearing that ensures the ground as well as holding the bearing...I think.

[Roberts440]

Thanks guys.  The steering column, or housing, is being adequately grounded by its mounting hardware, and I do see in the FSM an extra connection from a steering column cable cover mounting screw to the dash.  And I also concur that the bearing retainer provides an electrical connection to the outer race of the bearing.  What I am seeing is that incredibly the bearing is insulating its inner race from its outer race.  And it's the inner race, and the steering inner shaft itself, that must be grounded to provide the ground path to the horn button when pressed.

I think I will just do something ugly, and run a ground wire to the steering wheel to can assembly stud, and just try to use some very flexible wire that will withstand the wheel-turning twisting.  I'll post pictures if it works.  It won't be the first time I've 'assisted' the factory wiring.

[1970A-66Challenger]

It's been years since I rebuilt my column.  When I took mine apart I recall that the rubber isolator for the upper bearing had a small metal staple through it which seemed odd to me. After researching this my conclusion was that this staple provides the grounding path for the shaft (and horn switch) through the bearing into the housing.  But I could be wrong....

[Roberts440]

The staple idea sounds like a plausible explanation to me.  I suspect it wasn't supposed to be the only ground, but perhaps a backup to the possible paths provided by the bearings themselves.  I've quit for the evening, but tomorrow I'm thinking of fabricating a sort of 'brush' out of phosphor bronze to ground the shaft.  Thanks again to all.

[usraptor]

Cody has several excellent videos on steering columns.  Might want to watch these to see if they might answer your questions. https://www.e-bodies.org/videos/

[Roberts440]

I watched the excellent Cody video on assembling the steering column.  Ironically, he says he discards the 'staple' from the bearing.  I assume from the video that the grounding relies on the lower shaft coupling.  I reconfirmed that for whatever reason, I don't have continuity through my coupling.  As a quick fix, I fashioned a copper wire bypass around the coupling.  For added insurance, I also fashioned a bronze 'brush' to contact the steering shaft from the bearing retainer mounting bolt.

[Roberts440]

I thought I should follow up on this.  I had to remove the bronze 'brush' ground that wrapped around the steering shaft.  The turn-signal cancel rod apparently grabbed it and twisted it up enough to make the horn go off.  Embarrassing.  The lower coupling bypass still seems to work.