[T3] 1966 Type 3 Squareback ( non-functioning horn)

[Sean Bartnik]

Hey Gary,
I’m a believer that a good loud horn is essential, but then I live in NYC and also ride a motorcycle :-)

It’s not a very complicated circuit to troubleshoot once you understand how it works.  I don’t think you would need to pull the tank at all as for the most part everything can be accessed by removing the left front wheel.

The way the horn works is it gets constant power from the fuse box via a black/yellow wire.  There is a ground wire attached to the horn that runs back through the same harness bundle to the area under dash above the fuse box, then there’s an inline connector there. After the connector, the wire runs up into the steering column with all the other turn signal switch wiring.

If you pop off the steering wheel center cap you will see a wire connected to the horn ring.  That wire runs down the center of the steering column, connects to a washer on the steering coupler which passes the ground through to the steering gearbox housing.  Then there is a ground wire run from the top of the steering gearbox housing to one of the axle beam bolts which you can see with the left front wheel off.

When you push the horn bar at the steering wheel all you are doing is connecting these two ground wires together to complete the ground circuit.

So the easiest to check first because you don’t have to take anything apart is to disconnect the ground wire from the horn itself, then run a jumper wire from the horn ground terminal to any good body ground (the front hood latch works well for this).  As soon as you touch that jumper to a good ground the horn should sound (so be prepared for it).

If it doesn’t, then you either have no power to the horn (measure for voltage on the black/yellow wire) or the horn itself is dead.

NOTE: I’m not sure exactly when they switched it, but at some point they made it so the horn only gets power with the key on.  On my ’65, the horn gets power all the time, even with the key off.  

So the easiest possible solution is that the horn is getting power but it’s just dead and you replace the horn and move on with your life.

If the horn sounds when you jumper the ground wire but doesn’t sound when you push the horn bar on the steering wheel, then you have to find out where the ground circuit is being interrupted.  Often this seems to be where the ground jumps the steering coupler.  If the wire has broken or the spade terminal has rusted away, it won’t work.  But do the check above first and then report back.


> 
> I know we talked about this, Jim.
> And none of your Type3's have functioning horns, but you feel having a
> functioning horn is not important ... at least, not to you.
> 
> IIRC, you believe "tracking down" WHY the horn doesn't work, is a waste of
> time.
>