Air Horn Wiring

[Eulalio]

I bought this to replace my stock horn. Followed the wiring down to a tee but the horn does not activate. I direct-wire-tested the compressor to the battery and it works. I suspected the relay is faulty, any idea what to do next?

 

[mrjp]

Did you wire the white wire to a good ground?

 

[Eulalio]

Black and white to ground.
The Blue & White to the OEM horn wire.

 

[BLACKJKU]

Black and white to ground.
The Blue & White to the OEM horn wire.

Depending on how you look at the black and white wire it almost looks white at the ring terminal.

 

[TROY66/68]

You can bench test the relay to see if it is at fault. 12v supply and DMM set to ohms.