Horn Baffles Me - Now Always On

Gotta love that wiring . . .
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supplyguy

Horn Baffles Me - Now Always On

Post by supplyguy »

Air horns on '71 worked once in a blue moon (and never when being cut off in traffic) and now not at all. Read many threads here and went in today. Fuses all good and confirmed power to the middle of the three connectors on the original relay. Cleaned the connectors thoroughly and applied dialectric grease. Even scooped out a quart of solid oil sludge from one of the horns and cleaned them up nicely. Reinstalled, and damned near blew my ear drums out when I connected power to the relay. Here's where I may have really goofed. Toying with the relay innards (photo below) I pondered whether the ground contacts should in fact be in contact all the time, and pulled them slightly apart - where they remain. Reassembled, and again when wired up and I push the ground contacts together the horn honked me. Are they supposed to be in physical contact all the time, or should they be separated and some magical current close the loop?

Came in the house, logged on here, and found more info on horn button problems. So removed the horn button, reattached the power, and no horn. That said, the contacts are permanently gapped now due to my perhaps foolish improvisation. Thoughts?

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Danq
Posts: 43
Joined: Thu Jun 09, 2011 11:07 pm
Your car is a: 1981 2000 Spider
Location: North East Ohio

Re: Horn Baffles Me - Now Always On

Post by Danq »

Supplyguy,
Your relay looks good. The two contacts should have a gap between them when there is no current applied to the coil. The coil is the teal colored cylinder. The coil is a small electromagnet. Put a current to the coil and the bar at the left of the relay will be pulled to the right and the contacts make contact and the horn go honk honk. There should be four terminals on the base of the relay, 2 for the coil and 2 for the contacts. With the cover off of the coil identifying the terminals should be easy.
Dan
1981 spider 2000
supplyguy

Re: Horn Baffles Me - Now Always On

Post by supplyguy »

Thanks Danq. I only have three connectors (marked on the FIAMM housing from left to right "T", "B", and G". G was connected by blue wireto the air horn compressor and T and B ducked into the wiring bundle. The center tab (B) was hot and T appeared to be a ground. The contacts on the relay had been stuck together in constant contact, although the horn blew not at all before I cleaned the terminals. So if not the relay.....into the horn button? I removed it but it seems like simple technology - a spring that keeps the copper backing to the horn button from touching the metal ring in the steering wheel. How could this go bad? If it's inside the wheel - taking it back to G&S - I am quickly getting in over my head between this and the wipers (and the turn signals!).
User avatar
Danq
Posts: 43
Joined: Thu Jun 09, 2011 11:07 pm
Your car is a: 1981 2000 Spider
Location: North East Ohio

Re: Horn Baffles Me - Now Always On

Post by Danq »

Supplyguy,
Terminal B should be connected to the coil and one of the contacts, opposite of the contact connected to G. When the horn button is pressed, the circuit is closed. Current flows from the fuse to the the coil AND the contact opposite of G, through the coil, to the horn switch and finally to ground.
Check the wires to and from the horn switch and check the connections of the wires to the slip ring.
Does the contacts on the relay move when 12 volts is applied to terminals T & B?
Dan
1981 spider 2000
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