190e anti-theft alarm
 

All my alarm does is make a half second "chirp" from the horn when it is set off, and it does not go through its usual routine of blowing the horn repeatedly. Could this be a bad horn or something else?

My regular horn works fine, but I believe the anti-theft and regular horn are seperate units.

Why not try putting 12v to the alarm's horn and see if it works?

It is a separate horn located on the left front fender near the ABS unit.

Tinker