I have a 2009 Road King Classic and the horn has stopped working, stopped most of the time. The horn is good, wire to battery and works, wires at the horn have 12v when horn switch is pushed. I'm now lost as to what it could be. I have hooked a 12v light in place of the horn and although there is 12v there the light doesn't light. Any idea?

 

Ground?

 

12V and horn or test light doesn't work. That's called a ground problem.

 

Try spraying it with WD-40 while pushing the button. Yup, no BS, inside the horn itself.

 

Thanks for the information, how would I go about checking the ground, sorry for sounding stupid.

 

Pull the horn off and test it. You said you had 12 volts out of the switch - where did you test that? Test the ground wire from the horn (continuity) to either the frame or where it terminates. Clean all your terminals really well.

 

How did u wire it to the battery? Just hot or ground as well. They both have to be good at horn for it to work. If u took horn off and hooked directly to the battery then +1 on ground continuity check

 

I have taken the horn off and checked it directly with the battery and it works fine. I checked the wires on the horn and it has 12v. I put a test light and it doesn't light up. How is that possible, 12v with a multimeter and the test light doesn't work?

 

which wire is the ground wire, there are 2 wires, one black and one yellow. Thanks.

 

The ground wire is black.
12V is yellow/black.