Horn doesnt work. Where to start.

The horn didn't work before I changed my belt.

PS - the belt problem has been all sorted out.

 

That would lead me to believe it's the switch. Is your truck part of the spiral cable recall? I'm no Tacoma guru but I'm pretty sure the wiring runs through it for the horn.

Fry-Did you check the fuse for the horn? I'm going to put my money on this being an electrical problem as well. If not you can have someone press the horn on the wheel while you check for power at the horn itself with a multimeter or test light. I've never seen a horn just die but it can obviously happen from previous responses. You can also get water/mud up inside of it and it wouldn't work but it would more than likely just be muffled and your horns look clean.

 

I pulled the fuse but i dont know what im looking for. The small fuses are clear and i can easily see if they are blown. But the big horn fuse is opaque. I pulled it and looked at it. What is it supposed to look like when its blown?

 

Look at section F. It's a diagram of the underhood fuse/relay box. There is a ten amp fuse for the horn AND there is a relay. The fuse is translucent and like any other fuse, you can check it visually. The relay is opaque. Sounds like you are looking at the relay.

Correct way to diagnose this is to check for power at the horns themselves. If there is power, the horns have failed. Not real likely that they both are gone already on this age of vehicle, but I have seen it happen.

If there is no power at the horns and the fuse is good, start checking for power at the contacts where the relay plugs in. There should be constant power there at two pins, and switched ground at one pin. The fourth pin is positive power out to the horns. If you have constant power and switched ground, then you have a bad relay. If the ground isn't there when pressing on the horn pad on the steering wheel, then the most likely problem would be the spiral cable. It could also be a wiring issue or a bad horn pad. I believe the horn pad is part of the airbag assembly.

Check the fuse, check power at the horns and horn relay. Swap the relay with another identical relay if possible. Beyond that, I think you might be over your head, best not to mess with airbags.

 

Yep, I was looking at the relay durrr... My fuse is fine though. When I have my hands on the proper tools I will check for power at various places.

 

I wouldn't imagine the actual horn assembly is bad after only 4 years...

Check the relay. Quite simple actually.

-Open fuse box.
-Locate the wiper Relay
-Remove wiper relay.
-Find another relay that is identiacal to the one just pulled.
-Remove it and place in the horn relay location.
-Test horn.
-Works or it don't.

Test for power to the relay..
-Take a test light.
-Wrap a paper clip around the tip
-Remove horn relay
-Ground test light
-Test for power at each tab for the relay, does it have power going to it? (test light lights up)
-If yes, more than likely a bad relay.