Okay since my old horn, well lets not kid ourselves it never had one, I pulle doff the grill and saw 2 wires with contacts rotted off a very rusty small horn, so instead of trying to fix it I just went to crappy tire and purchased an air horn kit they had for sale there, nothing major like I have seen but enough to get some noise going and to scare the bears away in the woods by the cottage. Now I recieved this kit comes with a compressor with a positive and a ground and a 4 prong relay two horns ans some piping, not the horn works very well(my ears were ringing for quite some time)


Now I got two wires coming for the OEM horn on recieves a constant 12V power source and the other is the ground. Now the way I had it hooked up was like this.


Now the problem I am having is once I hook it up this way as soon as I connect the positive battery the air horn goes off and does not turn off. Now I am under the assumption this is incorrect since the OEM horn recieves a constant 12V source and when you press the horn button completes circuit grounds out and BEEP BEEP. So Can anyone explain if its possible to make a relay run as a ground switched relay? If anyone has a how to on how they did it on theres would be amazing. I need to get this running for inspection.
Thanks

 

sometimes those air horn kits have crap relays try anotherone

 

This could be true, Ill pickup another one on the way home from the shop. and see. It clicks when a ground is completed and trips so who knows.
Thanks
steve

 

Your diagram is missing a switch to turn it on? You use pin 85 or 86 as your switch input, can be either +ive or -ive. Toyota horns are -ive switched...find your stock horn switch wire (the ground wire you speak of) and run it to pin 86. Pin 85 is fine as per your diagram but 86 needs to be connected to your horn button. (-ive). The compressor should be grounded solidly (with the horn is a good idea) NOT to pin 86 like you have shown.

At the moment the relay is essentially hardwired, has a constant ground and constant power.

 

try this way too

 

You almost got it mate...In the diagram by Elton the only error is the pin 86 connection. No switch is necessary here. Pin 86 should be constant 12V, use the OEM connector 12V as it is already fused. Pin 85 is where the switching occurs....as i said the stock horn button is a -ive switch so use it.

 

The way I would wire it is different from the schematic you posted, especially since you are replacing the stock horn instead of integrating the air horn into the system
there is basically 2 circuits here one to power the relay, and one to power the accessory, in this case the compressor

1] original horn hot wire to the 85 post.
2] original horn ground wire to the 86 post (this should only complete the circuit if the horn button is pushed) this completes the first circuit, testing can be done at this point to be sure the relay only "clicks" when the horn button is pushed

3] fused 12 volt supply to post 30
4] wire from post 87 to the positive of the compressor
5] compressor negative to frame ground, or back to battery -
6] reconnect the battery, and test away

Good luck