Help me diagnose my horn...

[pritch]

When I was changing my cancelling cam for my blinkers, I foolishly did not disconnect my battery, and I shorted something out in my horn circuit. Now, I can't figure it out. Is there a fuse or fusible link anywhere in the circuit? I replaced the relay with a known good one and that didn't help.

I need to get this fixed so I can pass inspection-it's the only thing that don't work.

Thanks.

[Square_78]

Put a push button on the dash in the meantime until you figure it out. Horn doesn't have to be on the steering wheel. That's what I did on mine.
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[LockDoc]

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Does your relay click when you push the horn button?

Here is an older thread but it has some good info in it.

http://67-72chevytrucks.com/vboard/s...ad.php?t=99627

LockDoc

[ole dollor]

the horn should have a fuse at the fuse box, get a test light and check your fuses....and check your wires coming out of the turn signal switch down the column , make sure none have been burnt ...this is a place to start.

[pritch]

Originally Posted by ole dollor

the horn should have a fuse at the fuse box, get a test light and check your fuses....and check your wires coming out of the turn signal switch down the column , make sure none have been burnt ...this is a place to start.

This sounds more plausible, a fuse blown. I'll look again at my fuses.

[ole dollor]

would be nice if it was something simple like that ...good luck

[VetteVet]

The horn circuit is one of the simplest ones on our trucks. it is just three wires and they consist of ,
1. The red power wire from the engine compartment through the firewall plug to a 4 way junction one of which runs to the horn relay located on the firewall below the steering column.
2. The dark green wire which runs directly back through the firewall plug to the horn.
3. And the black wire which is connected to the red wire through the relay contact coil and when grounded it activates the horn relay and connects the red power wire and the dark green connecting wire that goes to the horn. This black wire runs to the steering column connector and up to the horn contact button below the steering wheel. When the horn button is pushed it is supposed to ground the black wire and activate the horn relay, connecting the red and dark green wires and sending power to the horn.

If this wire is grounded and the relay clicks the horn should blow. If the relay doesn't click when the horn button is pressed then the horn relay is bad or the ground wire is not touching the ground in the steering column.
If the relay clicks then the horn is bad or not getting power or the power to the relay is open.

There is no fuse in the circuit that I'm aware of.

You can run a wire direct from the battery positive to the horn terminal to test it. If it blows then it's good. If it doesn't then take it off and clean the mount and try again as was suggested. The surefire way is to take it off and put the mount on the negative battery terminal and then touch the terminal to the positive terminal on the battery. If it blows the horn is good, if it doesn't then you need a new horn.

If the horn tests good then make sure the radiator shroud is grounded to the battery negative. Then reconnect the green wire to the horn and jump the red wire and the green wire on the horn relay connector. It doesn't matter if it's connected to the relay or not. If the horn blows then the green wire is good and the red wire has power on it.

IF it doesn't blow then test the red wire for power and the green wire at the horn when it is jumped. The green wire might not be making contact through the firewall block.

I'm being redundant here but if the horn blows then plug the connector back to the horn relay and ground the black wire from the steering column connector and listen for the relay to click and the horn to blow. The most common cause is that this black wire is not grounding in the column at the horn contact or the wire is open.

[Mister-B]

Originally Posted by pritch

When I was changing my cancelling cam for my blinkers, I foolishly did not disconnect my battery, and I shorted something out in my horn circuit. Now, I can't figure it out. Is there a fuse or fusible link anywhere in the circuit? I replaced the relay with a known good one and that didn't help.

I need to get this fixed so I can pass inspection-it's the only thing that don't work.

Thanks.

Hi Gary,

I assume you had to remove your steering wheel to do the cancelling cam job? I wonder if this is as simple as not getting the horn button parts mounted back in properly? It's easy to get something pinched or mounted slightly wrong
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[pritch]

Originally Posted by Mister-B

Hi Gary,

I assume you had to remove your steering wheel to do the cancelling cam job? I wonder if this is as simple as not getting the horn button parts mounted back in properly? It's easy to get something pinched or mounted slightly wrong
Posted via Mobile Device

Yeah-steering col all taken apart and then I kept causing the horn to honk so-and this is the best part-I got out and unhooked the horn instead of the battery, and went back to work. Next thing, a big fat spark jumped out at me and after that-nothing!

[pritch]

Success!

Turns out, there was nothing wrong with the wires. It was the nut behind the wheel. I had it put together wrong. The little spring assy that goes in the hole in the steering wheel--I had it in wrong. Now, I'm a honkin' son of a gun

[LockDoc]

Originally Posted by pritch

Success!

Turns out, there was nothing wrong with the wires. It was the nut behind the wheel. I had it put together wrong. The little spring assy that goes in the hole in the steering wheel--I had it in wrong. Now, I'm a honkin' son of a gun

Glad to hear you got it sorted...

LockDoc

[ole dollor]

Originally Posted by pritch

Success!

Turns out, there was nothing wrong with the wires. It was the nut behind the wheel. I had it put together wrong. The little spring assy that goes in the hole in the steering wheel--I had it in wrong. Now, I'm a honkin' son of a gun

congrats....well done