Inoperative Horn

[John_Mc]

Any help would be appreciated.  I'm not totally clear on the principles but I know that the steering wheel button is supposed to ground one of the leads at the horn relay and therefore closing the circuit and sounding the horn.  I have power at both sides of the relay and if I bypass the relay entirely, the horn will sound.  Is my next step to check continuity between one of the leads at the relay to the horn button on the steering wheel??  Should I just run a jumper wire between the hot from the ignition switch to the one side of the relay and see if it sounds??  I'm suspicious that there is a break in the wire from the horn button to the relay.

 

Lastly, anyone have a decent wiring diagram for this system other than the standard diagram?  Thanks in advance.

[19tom40]

John, the horn button grounds one side of the relay circuit to complete the circuit to pick the horn relay. You the black wire comes from the horn button and has a connector at the bottom of the steering column. You can disconnect that connector and jumper the wire to the relay to ground. The relay should pick and the horns should sound. If they do sound, you will have to replace the wire in the steering column.

 

If the relay picks and the horns sound like a sick cow, you will have to clean the horn relay contacts. The original type horn relay cover comes off pretty easy, by slipping a thin blade on each side of the relay. Clean the contacts with a contact cleaner and a piece of paper. I don't like the use an abrasive on the points as that can ruin the contacts.

 

If the relay does not pick, check for voltage at the wire coming from the relay. Voltage at the wire will let you know that the wire is good and the problem is in the relay. I have a good original style relay if you need one.

 

[John_Mc]

Tom, I had a badly worn ground wire coming down thru the steering column.  I replaced it and the horn works perfectly, all the time.  Thanks!

Edited April 14, 2018 by John_Mc (see edit history)