Horn problem

Kenk · Post by **Kenk** » Wed May 20, 2009 2:53 pm

I bought a replacement horn that the owner said worked. My original did not although I seemed to remenmber the same test results. Maybe a higher voltage through the horn. I have a new wiring harness and horn switch installed. The new wiring harness only has one connector for the horn. The other I made up to go to ground at the fender. When i depress the horn switch, I get 24.5Vdc through my meter at the harness connnector to ground. Whe I hook the harness connector up to replacement horn, no sound and I get about 19.5 VDC from the second horn terminal to ground. Does it sound like another bad horn or am I missing something? Is these anything else I should check?

The horn switch has not yet been installed in the steering box and is working.

Thanks

Ken

Post by **Ryan_Miller** » Thu May 21, 2009 7:28 am

Is your ground from the horn to the fender or from the switch.

The horn needs to be grounded.

There should be two wires going to the horn.

Check the wiring diagram in the TM9 8012

Kenk · Post by **Kenk** » Thu May 21, 2009 3:06 pm

Ryan,

I was grounding the horn to the fender. Correct me but if I close the horn switch and with my meter, check voltage between the terminal on the horn going to the ground and the ground point, if I have voltage there, the horn should work. Does the master switch have to be on? It should not matter if I have voltage to the horn when the switch is closed.

Ken

Post by **Ryan_Miller** » Fri May 22, 2009 4:22 pm

In the M38 the horn switch is always hot. I looked at the wiring dagram and it shows the one wire is ground to the fender like you said.

I would test the continuity of the horn switch - without the button depressed and with it depressed. That should tell you if the switch is working.

Also check the horn.

I am no master electrical guru, but start there. Is the horn autolite or sparks-withington?

Cacti_Ken · Post by **Cacti_Ken** » Fri May 22, 2009 7:47 pm

For testing the horn alone. directly connect it to the 24 volt source mometarily, (the batteries) +24 volts & -24volts. This will of coarse eliminate the switch and wiring. Then you can go from there in your elimination of the other components.

oilleaker1 · Post by **oilleaker1** » Mon May 25, 2009 8:19 am

Sometimes while testing with the batteries, you can rap on the horn and jar it and it will come to life. Stuck in other words. I haven't looked at mine yet, but there may also be a adjusting screw to set the tone with. Moving this will also help jar it back into life. If the horn can be dissassembled, sometimes you can clean the points with fine wet or dry sandpaper and get them to work again. Good luck! Heck, maybe you can fix your old one too!

John