Horn problem - fixed! 1998 f150
I recently had a problem where my horn would not work. I did some searching here and found mention of the clock spring switch being faulty. I took that all apart and did not find anything amiss insde so instead of just replacing it I did some more testing. I found that if I unplugged the horn wire connector under the dash and jumped it I could still not get the horn to work. So this leads me to believe it is not the clock spring.
Next I went to the power distribution box under the hood. Here I found that I could pull the relay and jump the terminals here and make the horn blow. So now I tested the incoming wire to the relay (the one that actually fires the relay, not the power to the horn). If I put a voltmeter on it I get nothing with the horn wires jumped under the dash. I pulled the box out so I could get under it. I found the wire going to the relay was corroded so badly that it broke off. I pulled out the connector and replaced it with a shiny new one, reconnecting the newly stripped wire and now I have a working horn.
I didn't find any mention of this here recently so just thought I would share.