Horn

[DaveT]

looking for a little guidance. The horn on my 78, which worked fine, stopped working one day. I pressed the button and I got a faint sound from under the dash on the passenger side, then nothing. Three days later the horn worked for half my ride and then stopped working and hasn't worked since. Now when I press the button there,s a faint sound, almost a slight click that happens just once. Press the button a second time and no sounds at all. I don,t like electrics but I know I have to deal w/ them. Could the one-time faint click be a bad relay? Radiator fan works so I don't think it's the fuse.

[RRoller123]

It is probably the connections at the horn that are corroded, either the power or grounds. The "click" you hear is most likely the relay doing its proper thing. You can start by using a voltmeter to see if there is power getting to the horns. An assistant can press the horn button while the voltmeter looks for voltage at the horns. If voltage is getting there, check the grounds. If they are good, then the horn(s) (are there two horns on this year car? I don't know) itself has probably given up the ghost. For 1979 on, per my schematic, the left horn feeds the right one power, so if voltage isn't getting to the left one neither will work. If the relay is clicking on but no power is getting to the horns, you could check the wiring between the relay and the horns to see where the failure is. It is possible that the relay itself is bad, in which case no voltage would be read at relay output terminal 87 when the relay is "clicked" on. The power into the relay is through terminal 30 on the relay, and should read voltage all the time, assuming that your car's horn worked before with the key out of the ignition.

[DaveT]

Roller,
Thanks a lot for that. Hopefully there 'll be time to do that tomorrow.

[azruss]

check a couple of basics along with the electrical. when was the last time the compressor was lubed. should have a capped port on top for some air oil. what kind of shape are the tubes from the compressor to the horn. Sounds like you have power, but your compressor isnt spinning freely. Air motors need to be lubed regularly. Just a couple of drops will do.