Horns Run Constantly

[BrettHeintzman]

I have a 1965 Thunderbird and the horns run constantly so they have been disconnected at the horns. I have removed the horn frame and buttons from the steering wheel and disconnected the button wires complete. However, they still run constantly. Is there another wiring connection behind the wheel? I don't have a steering wheel puller but can go get one at the auto parts store. It does NOT have Cruise Control, so I believe there is no relay.
Any help will be appreciated.

Brett Heintzman
[email protected]

 

[ader6]

You have to remember that most of the wiring flows through harnesses. There is always the potential for a wire to get a brittle covering and become exposed or for a wire to rub off the covering. Another possibility is that a previous owner made a modification. My experience chasing out these problems requires three things: 1) Patience; 2) multi-meter; 3) The Electrical Wiring Book. Turn to the page for the horn circuit. See how it operates (e.g., does the horn button drop the circuit to ground to complete it or does it supply "+" to the horn. Notice the numbering on the wires in the book and use that to see what colors they are. Now start chasing wires with the multi meter looking for voltage (is it there when it should be and not there when it shouldn't be). Use the resistance setting to determine if wires have continuity (is the wire good or is there a break in it). Unplug things at junctions, fuse box, circuit breakers, etc and see if you get the expected results.

Good Luck

 

[BrettHeintzman]

Thank you for taking the time to respond! I kept digging in and here's what I found...

1) There is no horn relay in my '65 because it does not have factory-installed Cruise Control.
2) I pulled the Steering Wheel (quite and ordeal, but it finally came off). to discover the two bushings that, when bridged, closed the circuit and caused the horns to blow.
3) the two bushings touch two individual rings. Each of the two rings connects to either a yellow wire or black wire. These wires follow through to the horn switches where pressing them makes contact and closes the circuit allowing the horns to blow.
4) Someone had run screws into the steering wheel to secure the wiring that were not original and were too long.
5) These over-length screws touched both of the rings internally, thereby closing the circuit and causing the horns to blow constantly.

In the end, i ensured that the circuit was open all the way to the horn buttons, then rebuilt them accordingly, and got new springs for the horn buttons. Now everything works just fine.

Thanks again for your tips. Hopefully my discoveries will help someone else who is looking for this kind of advice.