[T3] Horn Issue

[Jim Adney]

On 31 Jan 2026 at 16:41, Max Welton wrote:

> I measured ~71 ohms between the shaft and the chassis. OK, maybe the
> wire is chaffed inside the tube. Disconnect the wire and test again.

Did you disconnect the wire at the bottom? Disconnecting it at the top won't 
help.

> Still 71 ohms. I would not have suspected the disk itself. It's just
> rubber, right?

Right, the coupling is just rubber and fabric. Should be a perfectly good 
insulator for much more than 6 or 12 V. The next thing to check would be the 
red wire from the horn into the steering column. Could it be pinched 
somewhere? If there's an inline connector in that red wire somewhere under 
the dash, take it apart and check the resistance on each side, to see if the 
problem is in the column or somewhere that the red wire works its way thru 
the body from the horn to the dash.

Somehow, that wire needs to connect to the outer race of the ball bearing 
the the steering shaft rotates in. That bearing sits in a plastic insulator at the 
top of the steering column, under the TS switch, keeping the bearing isolated 
from the steering column and chassis. The bearing makes the connection 
from the red wire to the steering shaft. I've heard of that insulator crumbling 
after so many years.

Unless you can find somewhere that the red wire is pinched, that insulator 
would be my next suspect. I don't know if anyone has replacements for that 
insulator. You might be able to get away with several wraps of electrical 
tape, or some large diameter heat shrink tubing.

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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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