Horn not working. how complex is the circuit?

[captainneo]

My horns have never worked. I replaced both horns with new, still doesn't work. I checked all fuses, fuses seem fine. what is usually a common problem with horns? I cleaned off all the connectors when I installed the new ones.

[pk2678]

A common problem with the horns is, that they are usually not loud. Because the wiring from the horn switch to the horns is very thin between the horn switch and a connector near the steering column.
Did you try the horns while the engine is running? Sometimes this additional voltage can activate them.
Fuse #6 for the horns is also used for the hazard switch. The hazard lights are working?
You can try to check the voltage at the connectors of the horns. If you don't get any voltage, the horn switch itself might not work or the wiring between the horn switch and the horns doesn't.

Here is some more information about the horn circuit:
http://dmctalk.org/showthread.php?11865-Horn-Circuit

--Peter

[DMC-81]

Check the ground, especially this one behindthealuminumcoolant pipe:



I replaced both of mine with OEM Mixo horns and they are plenty loud, so if even if they are new but weak, then there's definitely something wrong.

[JohnnyK]

I naturally assume your headlights are working. The horn is the simplest circuit. Have you started checking for 12+ve anywhere yet?

Probe the purple/black wire at the horn for 12v, and run a lead on the negative side of your multimeter to a known good ground (Which in this case, I'm guessing your only 'known' good ground is your battery -ve) and see if pressing the switch gives you 12v.

[captainneo]

Ok, i'll investigate those things.


Hazard lights work good.

[FABombjoy]

Left horn gets 12v first, has 2 wires crimped at the spade terminal w/ the 2nd wire running to the right horn. I had bad OEM crimp on my LH connector that took both out. The results of the 12v test outlined by JohnnyK will cut your troubleshooting tree in half and let you know if something similar has happened.