Horn malfunction

clusterbuster · 2012-09-26 08:38

I have done some checking of the horn circuit and found that I have plenty of power to both sides of the relay and the relay seems okay.. There is an open between the horn button and the wire that goes to the relay. Has anyone ever tore the steering column apart to change the wire or repair an open in circuit from the button to the relay? Mac's has a steering column horn wire assy for sale. I pulled the steering wheel and that didn't give me much insight as to where the wire is connected . I see the button that is on the top of the steering shaft. I works in and out freely. I have a ton of work on this old Custom 300, and this is just one of the many problems. Any help will be appreciated.

Ford Blue blood · 2012-09-26 09:31

That button is what makes the ground to energize the horn relay. On the realy put a ground on the contact coming from the steering column, if it energizes go to the button at the top of the steering column. Put a ground on the button, relay should energize. If it does that means there is a problem with the steering wheel contact. If it does not work look at the bottom of the steering box you should see a wire coming out of the center of the steering shaft, there is a connector about 2" out from the box, make it to ground to see if the realy energizes. If still nothing there is a broken wire between there and the relay.

Tom S · 2012-09-26 09:35

I know this seems simplistic, but ....
Did you get your multi-meter out & check for continuity between that button when it is pressed & the end of the horn wire where it attaches to the relay? Also from the button when pressed to anything grounded inside the car? The horn button just completes the circuit to ground.
Seems like sometimes just pressing the horn ring does not always work. Maybe something just needs a good clean up.
Here's a wiring diagram.
http://www.tocmp.com/tOCMP/wiring/5765wiring%20diagrams/Ford/MWire5765-195.jpg
Yeah, what Blue blood said... beat me to it.

clusterbuster · 2012-09-26 17:57

Thanks for the info guys. I did check the relay by fastening a test light to the terminal on the relay that feeds to the horn button. Light didn't go out when I pressed the horn ring. Should have when it went to ground. I do have the 57 Ford wiring diagram, but my relay battery feed comes from the hot side of the starter relay instead of the voltage regulator. Apparently it has been changed. I will follow up on all your tips when I get some time. Will let you know what I find in the future. Have family in the hospital now, so it will be sometime before I can address the situation again. Thanks. Don

clusterbuster · 2012-09-28 16:54

I feel kinda dumb. Guess what was wrong with the horn? This summer I switched the brake system over to a dual master cylinder, and during the installation of a front line, I pulled the horn wire connection apart without knowing it. When I got the diagnosis tip about checking the wire at the bottom of the steering box I found it disconnected. I really learned well about checking the horn circuit from you boys. Thanks again.

lowrider · 2012-09-29 08:54

DOH!!!!! I just did a similar thing on a HD Mikuni carb whose accel pump wouldnt work. Stop screw had vibrated out until the pump wouldnt work. This was after I had the carb off a couple times.

sprink88 · 2012-09-30 08:44

I REALLY hate when stuff like that happens

Zapato · 2012-09-30 11:12

Solid Proof that Murphy and his laws continue to be relevant.

Zap-

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Horn malfunction