Doing final vehicle prep work for the TTCW 09 and one of the things on the required list this year was a horn. I assumed this means a working horn and not the non-functioning one that has been sitting in the front of the SJ since I bought it. The reason for the lack of a horn is actually a bad grounding setup on the steering column but while I was in at Harbor Freight picking up some random items I noticed they had a little air horn setup for 15.95 that sounded like a lot more fun.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=40134Or if that is to much for you, they have a chrome version for a bit less
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=40135The package comes with a couple of horns, a Y to go between them, a small air compressor and a relay along with some instructions for wiring it in.
The instructions show you how to wire the system in while keeping your existing horn. I decide to just replace mine completely as it sounded a little sick anyway. Installation was placed up in the original horn location. This allowed me to use the stock blue wire as my ground switch while using the yellow as the 12v. This runs off of the fuse box using a 15 amp fuse that is plenty for this application.
I placed the horns on top of the unused jack mount that had been beaten down to save space. For the compressor I made a simple L bracket that just bolted through the back side of the grill just above the headlight. There is more room on the passenger fender but there is an ARB air compressor in the way.
This position also gave me easy access to the existing horn wiring. I simply split the 12v hot wire to two terminals on the relay. The blue wire ran to the dash, grounding it would open up the relay. I only had to run one extra wire over to the compressor. When the relay opens the compressor would get the full 12v signal and fire up. You need to run a ground wire on the back side of the compressor, but your battery is only a few feet away.
On a stock vehicle you would be done. Since my horn switch was already broken I just cut the blue wire under the dash and ran it to a momentary on push button then looped that back to ground.
Push the red button and a very loud and obnoxious noise blares out from the front end. Even with the hood down you can hear it without a problem. You can use only one horn if you want, the larger one has a decent sound. But the two together does make the best music. It is rather cheaply made so you will want to use some super glue on the horns to make sure they don't fall apart. I may go back this winter and build a better mounting setup for the horns that make it easier to access my air filter. Time will tell. But for under $20 this is a great way to get a little more noise under your hood.
