I just bought this 68 and the horn doesn't seem to be working. The horn is there and the wires coming off it seem to be going to the right place. Any advice on where to start my diagnosis?

thanks

 

Ground. Try running a ground across the rag joint on your column. I made a sometimes working horn blow steady by doing that. The cab is on rubber mounts and may not be grounding back to the engine, and to the neg. cable of the battery. A high percentage of all electrical problems on our trucks is because of bad grounding. :-)

John

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In the cool still quiet of night you can hear chevies rusting away.

 

Could be a bad horn relay. Could be a missing brush under the horn button/ring. Could be a bad horn. More times than not though, it'll turn out to be a faulty ground like John said.

Dan Blackwell

 

I would look at the spring loaded brush under the horn ring. Make sure it's there and in good condition. Make sure the surface it rides on is clean also. Easiest place to start.

Kevin K.

 

Run a jumper from the battery positive to the horn power connection. If you aren't deafened the horn is dead or the ground is bad. Clean the ground, which is the horn mounting bolt and try again. No beep=dead horn.
If it does beep then find the horn relay, passenger side under hood on or above inner fender. It will have 2 yellow wires and one blue/yellow striped wire running to it.
Remove the connector and jump the 2 yellow wires together, if the horn blows it isn't a fuse or the power wire circuit. If it doesn't blow check the fuse or if the truck is so equipped there could be a fusible link instead on the starter relay, large terminal where battery positive connects.
Reinstall connector and ground the blue/yellow striped wire if the horn works now the problem is in the ground circuit from the horn button.
Remove horn button ground out horn contact stud. If horn blows the contact isnt touching the horn button contact brass ring or the horn switch is dead or there is an accumulation of dirt.
If horn doesn't work check the rag joint grounding wire.
This should get you started. Good Luck.

Sparky

PS
Common problems are, as stated before by others, horn contacts under horn button broken or dirty, ground strap across rag joint missing, blown fuse, sometimes but not often dead horn relay and of course the ole dead horn itself.