72 Super beetle. Steering column isnt grounded. No horn

[talljordan]

As above.

I get a solid 12v at the horn wire in the steering wheel, if I touch this to a well grounded wire, the horn blares. But pressing the horn does not work because the steering column itself is NOT grounded.

I measure infinite resistance between the steering column and ground, unless the car is off and the column locking pin touches the column.

How could this happen and be fixed? Corrosion between the u joint and the bottom of the column? Is the u joint itself isolating it? How can I add this ground.

Hopefully @ashman is around
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1972 Super Beetle, Parked until adequate restoration funding is acquired in restoration!

Wanted: Male computer diagnostic plug end

[baldessariclan]

For Super Beetles, the steering wheel shaft should effectively be grounded via its metal-to-metal connection to the steering box’s worm shaft — ref. pic of said connection point near the end of this post: https://www.thesamba.com/vw/forum/viewtopic.php?p=10175381

And if a metal anti-rattle bushing is installed between the shaft and upper column bearing, that should act as an additional grounding point — picture of that from the above post as well:

If your steering shaft is not showing continuity between it and known good body ground points, then I would check/clean at the steering shafts’s connection to the steering box’s worm shaft. Another check would be to see if the steering box itself has a clean connection and is well grounded to the rest of the body.
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1971 Standard Beetle — fairly stock / driver

baldessariclan -- often in error, never in doubt...

[talljordan]

I sorted it out! Took damn near all day but the horn works now.

I tried to investigate using the original anti rattle bushing in the upper column, but my bearing is of a design that if I used it it would expose the ball bearings. So I ruled this out.

I worked out that the steering box wasnt grounded either because of the fresh paint, so I pulled one of the bolts, ground out the paint where the washer touches the body, and screwed it back down. Still no horn.

At this point, I pulled the whole damn steering assembly out. Turns out the bleeping u joint shaft is electrically isolating somewhat. I read a few hundred Ohms end to end. I added a wire from the top clamp nut to the bottom, and no more issues! Horn works perfect.

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1972 Super Beetle, Parked until adequate restoration funding is acquired in restoration!

Wanted: Male computer diagnostic plug end

[baldessariclan]

Interesting — looks like might be an aftermarket/replacement shaft, maybe? I’m not seeing the usual “VW” mark on the end castings, anyway. If aftermarket, who knows what sort of bearings are in the u-joints, and if their internal components are electrically conductive or not?

In any case, glad that you were able to figure out the issue, and then come up with a viable work-around!
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1971 Standard Beetle — fairly stock / driver

baldessariclan -- often in error, never in doubt...