Horn working intermittently

[Bob D]

Horn working intermittently, and only when steering wheel is turned.
Horn switch and plunger spring thoroughly cleaned, but still inoperative unless wheel is turned.
Plunger well has a brass bottom. I assume it must somehow make contact to a rotary contact that needs cleaning?
Is that the clock spring (what GM calls “Inflatable Restraint Steering wheel Module Coil”)?
Thoroughly pored through Service Manual, but could glean little.

[Bob D]

... it must somehow make contact to a rotary contact that needs cleaning?

Further research suggests plunger spring is hard-wired to ribbon cable integral to clock spring assy?

[efritz]

well, a horn is designed to work intermittently, if it were on whenever the truck was on that would be annoying.

 

 

 

 

 

 

I'm of no real help, just wanted to be a jacka**.

[8.1HD/ALLISON]

Yes that rotary contact is the clock spring assembly. Guessing you have a pinched or open wire. If you can access both side of clock spring on the correct terminal, check for open with dvom wgile turning wheel.

[Bob D]

Yes that rotary contact is the clock spring assembly....

That's what I thought, but on examination of new clock spring, horn tower hole (where plunger spring inserts) is a pass-thru hole.

I'm guessing turn signal cancel cam is the rotary switch? Gotta tear into it & figure out.

[Bob D]

Horn Plunger Spring dead-ends in a well in the Turn Signal Cancel Cam.

Rear of cam is the rotary elec. contact surface.

There is a spring loaded copper pin in the Turn Signal / Multifunction Switch which makes contact with the cam.

I cleaned contact surface as well as I could without removing cam, only slightly better.

Can't find this part anywhere. May have to go to dealer.

(Wish Clock Spring WAS source of contact for horn. Would make things easier.)

[8.1HD/ALLISON]

Been a while, I was thinking it was all one piece. Let us know what you find.

[Bob D]

Let us know what you find.

Will do. May take a while. Had steering wheel apart a bunch-o times.

%*^ thing is trying my patience!....

[Bob D]

Well, finally got around to replacing Turn Signal Cancel Cam.

Horn still not working unless steering wheel turned!?

argh...

[Bob D]

Well, it's been a long while.

Ordered the Turn Signal / Multifunction Switch many months ago.

Finally installed. Horn now functions (regardless of steering wheel rotation).

[utah33]

Thanks Bob for you troubleshooting notes!  I have the same problem on my 02 Silverado.  I cleaned all the horn switch contacts, rung out the wires, and upon checking for 12 volts in the well, where I assumed the voltage would come from, I had not voltage?  I turned the wheel to different positions and discovered voltage would come and go.  So, Your problem is very similar to mine.  I guess I will be replacing the turn signal/multifunction switch.  I also discovered that the horn switch plunger went through the clock spring, so the clock spring has no connection to the horn.

[utah33]

Update on my horn problem.  I also, replaced the Multifunction switch, in my case the  horn still did not work? The reason I replaced it was I am also having some turn signal issues and since Bob said the switch fixed his horn I thought I would maybe knock out to birds with one stone.  Not!  I had some work done by a mechanic and mentioned my horn not working and he said, the contacts on the switch sometimes get worn down and can be turned over?  When my horn was working I rarely, used it.  I don't see how the contacts could be worn?  None the less I will check them when I take apart again.