Electrical gremlin sounding the horn?

[All_talk]

Hey Guys

 

I was working in the shop Friday night and horn in my ’87 GL wagon went off, I found the fuse and pulled it. I poked around a bit and found nothing amiss so I started the car and put the fuse back, no horn blowing and all seemed fine. About an hour later the horn came back on, same as before, start the car and it goes off, turn car off, 15 min later the horns back on. So I left the fuse out the rest of the weekend (didn’t drive the car), I put it back this morning before my drive to work (about 1.5 hours), horn came back on about 2 hours after I got to work. The sound is a lower tone than when you honk the horn, like its just one of the two horns (I assume they are the Hi/Low type) or its receiving reduced voltage. It really seems like a ground issue, the Chilton’s manual electrical drawings aren’t very good but they do show a diode in parallel with the horns, maybe its failing in a way that’s grounding, or maybe its a bad horn, but its very strange that it only does it with the car off and after some period of time. Any clues would be greatly appreciated.

 

Gary

[frag]

I think I remember (Former 92 Loyale) that the horms were relay activated. The horn button grounds the relay and make it send voltage to the horn. I think there is one relay for each horn (if my memory is exact)

So maybe one of the relay is grounding itself some way on another.

Know it does'nt help much but that's my 2 cents.

Good luck.

[CIS Subaru]

I had an '85 Sedan that did the exact same thing. I never figured it out, so I just ran a new wire for the cruise control and left it hornless.

[Skip]

Gary, the horn on our cars (I have two 87's) have no horn relay (sorry Frag)

They work on a negitive switch. By this I mean

battery voltage is fed to both horns in parallel via the fuse.

The other contact on each horn is fed to the pad on the steering wheel.

To sound the horn the switch under the pad grounds this wire.

You could check this pad connection for an intermitant short to ground or

look at the wiring to the horns.

This is done by removing the head light (4 - ten mm nuts)

the horn and it's wiring is visable after they are removed.

One on both sides.

Any short to ground on the wire to the steering wheel will blow the horns.

Hope this helps

[baccaruda]

a fun little trick is to hook up the brake light switch on the brake pedal to the horn circuit... every time you touch the brakes, BLLAAAARRRTT!!!

[All_talk]

I found the problem , the right side horn had failed and corroded to the point that it was creating a partial ground, a check with the ohm meter confirmed it. BTW, I removed the park light to get to the plugs and the lower valance to get to the horns themselves, though removing the headlights as skip suggested might have been easier.

 

Thanks for all the input.

Gary