The horn system isn't complicated...I suspect you have merely blown a fuse if you wired the compressor directly to the leads off the factory horns.

As posted earlier, the compressor is a heavy current draw, and the kit normally would have supplied a relay.

I have a Hella air horn kit in my VW, and with a 45-amp alternator, there is not a lot of juice available for high-current accessories. With the relay, everything works fine.

You can use the factory horn leads as a switch and ground for the relay, then splice a high-current lead for the compressor to power up. The current draw for the compressor is less than 16 amps (that's the highest current that can pass through my VW fuse box), so make sure you put an inline 15-amp fuse as well.

You may have noticed that your horn takes a bit longer to blast, since there is a lag time for the compressor to spool up?

Oh yeah, another tip...angle the trumpets slightly downward to allow any moisture to drain out. Otherwise, dirt and water will get collected and trapped in the diaphrams, rendering a short life for them.

__________________
2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car