Today my 86 Fiero started to honk the horn randomly. Eventually, the horn stayed on. I wiggled parts on the fuse board around and it stopped.
Next I noticed a vibrating from a relay underneath the passenger dash. It wouldn't make the noise when the doors were open and my radio was going on and off. I looked at it and the bottom was busted out. I took it to O'Reilly's and they said it was the horn relay. Okay, that explains the horn, I thought. I switched it out and noticed my battery fuse had blown. This explains the radio. I then switched it for another fuse and it blew immediately.
Then I tried again and it was fine... until I turned the car on. I got a buzzing noise from the relay I had replaced until the battery fuse blew again and the buzzing stopped.

Any ideas as to what is happening?
Did they give me the wrong relay? Is my fuse the wrong size? (25A is what was in there).

Update,
I detached the horn and the problem persisted. I decided to just detach the horn relay and the problem is gone.
I would still appreciate some feedback if anyone knows what is happening.

It's supposed to be a 20 amp fuse.

New parts are not necessarily good parts.

Years ago my shop was looking for reason why the horn would blow the fuse on a chev pickup truck. We finally traced it to a splice under the dash in the harness that connected the horn fuse and lighter fuse to power up the lighter and horn. The engineers made the wires undersized. It turned out the cigarette lighter has semi melted and was shorting out the plug somewhat causing a drain. Disconnect your lighter and try the horn again. This sounds sooooo familiar.

P

Yeah the radio and cig lighter fuse are the same circut, (hold down the cig lighter, the fuse blows, the radio quits and usally the brake light will come on, as then it is back feeding a circut) just an fyi

Batt fuse circuit. It's only part of the radio power, but all of the cigar lighter and horn relay.

[This message has been edited by Gall757 (edited 03-03-2015).]