Horns

[BenRoberts]

The horns on my 923 were inoperable when I bought it and im looking to troubleshoot it but I dont know where to start. There is no movement in the horn pad on the steering wheel when I press on it which I guess would be somewhere to start.

 

[Recovry4x4]

That sounds suspect. There is a section in the TM dealing with the horn but basically it's always hot and the horn button establishes the ground.

 

[ralphluby]

The horns are dependent on air pressure. Start up truck ,build up pressure and there is a good chance your horns will work

 

[BenRoberts]

The horns are dependent on air pressure. Start up truck ,build up pressure and there is a good chance your horns will work

The truck holds around 120psi but it did sit with the top off for a long time before I got it which leads me to believe its something in the cab thats got too much rain in it.

 

[Wildchild467]

I also had the diode in the horn system go bad in my buddy's truck which caused the horn to stick on. good thing is that its not that complicated of a system. A basic volt meter/test light and flare nut wrench (to loosen the air line to see if you have air to the horn) and jumper wires should be all you need to troubleshoot. Like Recovery 4x4 said, the horn has a hot wire going to it and the horn button only supplies the ground.

 

[BenRoberts]

I also had the diode in the horn system go bad in my buddy's truck which caused the horn to stick on. good thing is that its not that complicated of a system. A basic volt meter/test light and flare nut wrench (to loosen the air line to see if you have air to the horn) and jumper wires should be all you need to troubleshoot. Like Recovery 4x4 said, the horn has a hot wire going to it and the horn button only supplies the ground.

Ill tear into her this weekend, thank you for all the advice

 

[The HUlk]

I replaced my stock air horn with an aftermarket one recently and can give you some specifics on what to look for electrically:

As was mentioned with the ignition on there should be constant +24V on wire 26 at the horn. If not then the circuit breaker at the top engine side of the firewall just right of center is suspect.

When the horn switch is pressed there should be GND supplied to wire 25 at the horn.

 

[BenRoberts]

I replaced my stock air horn with an aftermarket one recently and can give you some specifics on what to look for electrically:

As was mentioned with the ignition on there should be constant +24V on wire 26 at the horn. If not then the circuit breaker at the top engine side of the firewall just right of center is suspect.

When the horn switch is pressed there should be GND supplied to wire 25 at the horn.

Now that you mentioned the circuit breaker it has me intrigued. I believe the horn pad is stuck down and id wager to say the breaker was pulled but looks like I got a date with the power probe this weekend.

 

[gerrykan]

.....looks like I got a date with the power probe this weekend.

 

[BenRoberts]

horns now work, The contact point where it grounds was so rusty it could not provide a good ground. Took everything apart cleaned it and its back in action.