Originally Posted by Bouchbri25
My 1989 ford f53 chassis keeps blowing the horn fuse even with the horn unplugged. What else plugs into the horn fuse and what could be causing this?
My guess, and only a guess, is there is a horn relay that is operated by the horn button. When you push the button it completes the circuit to pull the relay into the closed position and the current to the relat then goes to the horn trumpet. My guess is the horn relay is shorted or possibly worn/missing wire insulation on the wires to the relay.
Track the wires to see if there are any points that are shorted because of this. If not then try engaging the relay by grounding the wire that goes to the horn button/steering column while you have 12V to the relay. You should hear the relay click when you do. If not then my guess is the horn relay is shorted internally.
Also not unusual for the trumpet to go bad, but that is probably not the problem with the fuse, but may become the problem once the horn control circuit is repaired.