I am trying to figure out from the life of me how this horn circuit works. The wiring diagram leaves a little to be desired. This is what I have figured out so far:

The horn relay although decrepit looking, does seem to work. When I connect the relay as follows, the horns work when the makeshift switch is depressed:

Orange & Black (w/pink) heavy gauge terminal: 12 V positive
Black horn terminal: horns (which are grounded)
Green terminal: makeshift switch (which is grounded)
Black (w/pink) light gauge terminal: UNCONNECTED

How can I test the regular horn switch and what is the Black (w/pink) light gauge wire for? Horn seems to work fine without it.

Picture of horn relay with annotations attached (with File Manager)

Thanks for the help!

the schematics says one of the connections is key buzzer. i would hook it up and leave key in , or in the on postion and see if that terminal goes hot +12

it makes sense if you look at how it works. hot is supplied internaly to a coil and a pole, oK i'll try to explain the best i can . So it actaully serves two purposes, the horn obviously, and in default mode (not grouned for horn) supplies +12 for the key in buzzer.

+12 comes in on the center terminal , green goes to the horn button. black goes to the horns . so that just leave the black with pink.
in its default state hot will be suppllied to the black with pink on the right . if you run that to a small buzzer, the a wire from the buzzer to the key in switch that is only closed and grounded in the off position and the key in , the buzzer will sound reminding you the key is in ignition.

If you press the horn button , it energizes the coil pulls the latch down to supply +12 to the horn, at the same time it removes +12 from the key buzzer.

I can draw it up schematically if you wish.

Can I just not reconnect the key buzzer wire?

And also, how can I test the green wire? Right now, I inherited a doorbell on the center console for a horn (please hold laughter). It is wired direct to horn with a 20A in line fuse). In other words, I want to test the horn switch.

Yes you can just leave that off.


if you supply +12 where you have it stated on the picture along with hooking up the horns to the terminal as in your picture then ground the green teminal. your horns should sound. if that doesnt woek they relay is bad. if it does work connect you horn button to that terminal.
When you press the horn button it energizes the coil pulling the contact down to the pole going to the horns supplying +12 to the horns.

seems like a pretty over complicated way to enable a key in buzzer . rube goldburg if you ask me.

Here is what the inside looks like;



http://theyells.net/open-relay.jpg

i know a little over board but i was bored and i had just taken mine apart to make sure it works.

Thanks for the hard work PCI on that diagram.

Well, I figured out my horn relay works. I rerouted the ghetoo wiring job so it passes through the relay. But I had to cut out the green wire and splice that green connector to my adorable door chime by my center console!

Still wondering how I can test the horn button switch though!

ohm meter, pull horn button off wheel. make sure the spring loaded connector is good. Put an ohm meter on the green wire and ohm it out (it should be shorted), the horn connector button always wears out. its a solid wire from the horn button to the relay. they sell rebuild kits for the horn button. i may have a few kicking around.

ohm meter, pull horn button off wheel. make sure the spring loaded connector is good. Put an ohm meter lead on the green wire and connect the other lead from the meter to ground ohm it out (it should be shorted when the horn button is pressed), the horn connector button always wears out. its a solid wire from the horn button to the relay. they sell rebuild kits for the horn button. i may have a few kicking around.

Sorry some time my brain goes faster than my fingers!