03 Trailblazer Lock/unlock Problem

[nvsparky]

I have a 03 Trailblazer with a aftermarket alarm, recently the lock/unlock feature stopped working. The alarm company said I need to take it in and have something reset at the dealer. This stopped working at the same time I had to get the low beam headlights fixed. Any ideas if I need to take it to the dealer or is there something else it might be? The power locks still work if I touch the switch and the alarm works other than the this problem.

[ScottyBoy]

How long ago did you have the alarm installed? Most reputable shops will give you a lifetime warranty, hopefully yours has a warranty. It could be something as simple as a harness came unplugged, or a wire connection came loose. A trailblazer also needs a "module" for an alarm to control the locks. It could be that this lock module either has a loose connection or else went bad. A likely scenario is since you said this happened when you had your headlights repaired, the repairman was probably digging into the dash to get at the headlight switch and accidently hit a harness with his hand and it unplugged or something.