GRRRRR!!! Horn not working!!!

It helped me recently as well!

[HIGHWAY BY THE SEA]

I finally got to working on the 67 GMC again. Time to revisit the horn issue. I figured out today that the plunger on the canceling cam is NOT making contact. I was not able to get the horn to honk using the canceling cam plunger and the steering wheel mount bolt. It would work without the canceling cam though. Here is a picture of it with the plunger pressed down and it is not long enough to make contact as it should.



Here is a picture of the canceling cam taken apart, and the plunger is not long enough to make contact even pressed all the way down. This HAS to be the problem, because everything else seems fine. I got this canceling cam out of a 67 C10 in a junkyard. I guess it is a goner. Now I must find either another plunger that is longer, or a new canceling cam...

[dmjlambert]

The plunger does not need to go down and make contact with that metal ring. The spring is what conducts. The electricity flows from the spring plunger that sticks up out of the column to make contact with the cancelling cam round plate, then from the top side of the cancelling came it goes through the spring you show a picture of, then through the plunger, then to the convex spring plate that is part of the horn button assembly. All of those parts should be in constant contact with each other. Then, if the convex spring comes into contact with the center hub of the steering wheel to ground it, the circuit is complete and horn honks.

I had my horn stop working once and took the cancelling cam spring and plunger apart, although I didn't take the large metal ring off the plastic like you did. I didn't know that part came off. I cleaned up the spring and plunger and cleaned the bottom of the tower hole to make sure it was clean bare metal. That fixed it for me. I used some brasso metal polish on a q-tip.

[HIGHWAY BY THE SEA]

Well, the horn is finally fixed! It was in fact the plunger spring in the canceling cam. After I took it apart, I used a Scotch Brite pad to clean where the spring touches the brass on it. Even thought it did not appear dirty, this somehow fixed the problem. What makes this so odd is that the old canceling cam that I removed from this truck did not work with the horn either. Weird.

[Getter-Done]

Glad to hear you got it fixed.










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[Andy4639]

Good to hear it!

[DennisP]

Not bad! Only took you a year!

[HIGHWAY BY THE SEA]

Originally Posted by DennisP

Not bad! Only took you a year!

Yep! I put the horn on the back burner until I was able to get other issues fixed first!

Now on to the wiper motor...

[cdk]

With the info from this thread ,I got my horn honking! Thanks for the post !

[dmjlambert]

You're now a horn honker! Welcome to the forum. If you want to start a new thread and post your truck story and/or pictures you'll get all sorts of folks greeting you and giving you encouragement (if you need it). We like pictures. The manage attachments button is what you use to upload pictures.