OK... I've had enough of SUVs, minivans, and soccer moms... I picked up a set of Wolo Model 400 Airmite air horns from Pep Boys to install.

The unit came with a compressor, 2 horns, some hose, and a relay... I tapped into the horn +12v line and used that to turn on the relay for the air horns. This way the air horns will have their own power source and both the air horns and the stock horn will work at the same time...

Here is a pic of the finished install of the horns & compressor. I didn't take pics of the brackets as they were being fabricated & installed but they are very simple.

The bracket that holds the compressor is an L shape and I used a wide rubber washer between it and the bracket holding the AC lines to help dampen vibrations.

The bracket holding the horns is also L shaped but the end of the L is bent to fit up against the bracket holding the emissions canister. There is a piece of hose between the two to keep the paint in good shape and that along with the rubber washers help with vibrations. I put a slight bend in the long part of the L, between the horns, to allow for the horns to clear a couple of obstacles under the hood.

Here is an up close picture of the bracket holding the horns and where it mounts in the car.

All of this is fabricating required no special tools other than a vise (if you consider that special) and some small hand & power tools (drill & jigsaw with a metal cutting blade.) The vise and a hammer was just for bending the metal bar into the brackets and the jigsaw is just for cutting the metal bar, but you can always use a hacksaw instead.

After all of that was the electrical work... and DANG! It cost me almost as much as the airhorns for all the crimp connectors & wire. I used 12 gauge for the compressor power & ground and 16 gauge for the horn signal & relay ground.

The relay was mounted to the windshield washer reservoir mounting bolt as it was next to the fuse box.

I unhooked the positive battery cable and then hooked up an inline watertight fuse holder to the main connection in the fusebox and connected it to the relay. Here is where a nice magnetic pickup tool will help. The bolt that holds the main wire in the fuse box is short and easily dropped - don't ask.

Next was a run of 12ga red wire from the relay to the compressor and then a short run of 12ga black wire from the compressor to the mounting bracket I made for a good ground.

I used a female spade lug tap to tap into the horn +12v wire and ran a wire back to the power for the relay. A quick short ground wire from the relay to where the windshield wiper motor ground was installed to complete it.

After all of this, I go over to the driver's side door and push the horn button.... nothing. What the heck?

It's nice to have a kid to help when troubleshooting... I disconnected the stock horn to see if there was too much of a voltage drop to keep the relay from being activated. Nope. Wasn't it. Next was verifying all my wiring to see if I had something bad there... Nope. It was the relay. A quick swap out of relay with another one that was on hand and WOW!

It's VERY loud. VERY.

I reconnected the stock horn and now both work at the same time. This way I have more sound and if the air horns ever fail for some reason then I will still have the stock horn to make sound. The best of both worlds.

You can hear the sound of the air horns here. And, yes, Pep Boys did replace the defective relay.

Fit-n-finish:
The package comes with the 2 horns, 1 relay, 1 compressor, 1 Y connector, nuts & bolts for mounting the horns/compressor, and a length of hose. It does *not* come with any wire or wire connectors. The only issue I had with the fit and finish was that the relay was defective.

Bang for the buck:
VERY nice. Could've been better had I gotten the connectors and wire cheaper. This was a case of wanting to get it done NOW instead of waiting a day for the electronics store (Tanners Electronics!) to open.

Can I do it myself:
Yes, but the troubleshooting I did was made easier by having my son press the horn button :D

Time:
It took about 4 hours over 2 days to do this. This is mainly due to having to fabricate the brackets.

Extra materials required:
1/8" thick bar stock from Home Depot to make brackets

Red and black 12 gauge wire for the compressor

Blue and black 16 gauge wire for the relay

Assorted flag, spade, ring, and tap connectors - crimp style

Nuts/bolts/washers/rubber washers to mount the brackets for the horns and compressor.

An extra relay!

And finally... some Zip ties to hold the wiring in place.

Tools required:
A drill press (or just a plain drill) to drill holes in the brackets and to make the hole bigger to mount the relay

10mm socket/ratchet (and whatever size needed to fit the nuts/bolts you buy)

Grinder, file, or dremel to remove sharp edges.

Vise and a hammer to help fabricate the brackets.

Cutters & crimpers to do the wiring

Happy Motoring!