The horn on my went off by itself (continuously) last month when it got down below freezing one night. I pulled the horn relay to get it to stop, but I'd like to fix the real problem. I've seen some reports that as the steering wheel plastic ages, it shrinks when cold and this causes the problem. Has anyone had any success in going into the steering wheel to fix the horn switch? I'd rather not buy a whole new airbag/horn switch for this problem if I can help it.

 

Update: I narrowed the problem to the airbag / horn switch. After removing it, I found the problem - salt! I unscrewed the two Torx screws where the horn electrical connector is located, then I could pull the vinyl cover down (release the two tabs on each side) and expose the electrical contactors. Both the plastic membrane and (especially) the black metal part had little salt deposits all over them. I suspect that during the cold night, the vinyl pulled the membrane too close and some salt bridged the gap and completed the circuit. A damp paper towel and my fingernail cleaned everything up and now it's is back to working correctly.

Where did the salt come from? I'm in Florida, but an hour from the shore. I suspect it may be from 10 years of holding the wheel, but I can't say for sure. In any event, I wanted to post my fix in case it helps someone else.

 

my 1999 f150 has this problem, I went to the dealer to have them look at it, they told me that it would be $900, becuase they had to replace the airbag. I told htem to pound sand 'cause the truck has almost 200K miles on it, so there's no way I'd pay that much.

Anyway... Does anyone know how I can to the relay to see if I can fix the problem myself? I don't want to pay someone to fix this if I don't have to, but I'm in Texas, and the car inspection requires that the horn work. If I can do this myself I will.


Thanks!