Horn prioblem

[bonsaiwino]

So here's my horn's erratic behavior: when the car is parked & not running, the horn works perfectly. However, when the car's running, the horn only works sporadically. What's with that?! Thanks guys, Don

[aj81spider]

One thing to look at - not sure about your year, but on my 81 the horn and the fan are on the same fuse. It may be that when the fan is running there is enough voltage drop to keep the horn from running. This would imply a bad connection somewhere. Try jumpering the fan on and seeing if that affects the horn operation.

[bonsaiwino]

Hi aj, Mine's a '79. Thanks for your note. Your theory makes perfect sense. I knew that the fan & horn are on the same circuit. Now to find the nasty culprit in the circuit! Thanks, Don

[vandor]

The brass contact ring at the back side of the steering wheel may be worn. Two pieces of brass from the column switch brush against it to provide contact and over the years they can wear out, or wear out the contact ring.

[TX82FIAT]

+1 with Csaba to pull the steering wheel and look at the contact points and contact rings. Very common for these parts to have wear makes from the wheel turning in the copper or for little copper bits to bend out of place. When you pull the wheel it will be more easily understood.