DIY: Replacing the dead goose honk Audi alarm with a 118db horn! $21.99 completed

[Drftpretty]

Picked up a set of these from Autozone lastnight on my way home from work:

http://www.autozone.com/select...p.htm

I had originally planned to use them behind my front RS4 grille and to ditch my OEM horns. After quickly finding out that the horns would never fit behind the grille because they were too deep I decided to use them for the car alarm. [:D]

First thing is to locate the OEM Audi teeney tiny carm alarm. Its behind the interior carpet panel drivers side directly next to the OEM amp and CD changer.

You can see it here with the two wires un-plugged from it:



I didnt actually remove the trim panel so I couldnt get in there enough to remove the actual OEM alarm, I just pulled the female connectors off.

Next I went and picked up a piece of 10"x1" zinc coated angle iron for $1.99 at the hardware store and mounted one of the horns to it.



With it mounted I set out to find a place to mount it. On the drivers side dumper mount there are 4 allen head bolts attaching the bumper support to the frame. The lower inside bolt I took out right above the muffler. Seen here, bottom left:



Next I just had to find a way to run the wire from the stock alarm to the new position behind the rear bumper. I wasnt found of drilling any holes so I went looking for the spare tire drain plug.



I cut a slit in that plastic plug to run the wires through after I crimped on male/ female connectors. Then I simply ran the wires and plugged everything in.

MAKE SURE YOU DO NOT GROUND THE HORN TO THE CHASSIS, THE AUDIS HORN IS A NEGATIVE SWITCH SYSTEM!

Then I just bolted her up in place to the bumper support bolt and she worked!



I actually only hooked up one of the horns so if anyone wants the other Ill let it got for $10 shipped with a mounting bracket.