We've got a 01 Montaro and keep having a weird problem with the factory alarm. The alarm will spruattically go off in the middle of the night usually, this is the 2nd time we've had this problem. The first time we took it in to have repaired and they said they solved it but months later it's back. Two things I've noticed, 1. after it goes off I'll lock it with the remote and the vehicle won't honk like there is a door open.2. while I'm driving if I lean on the door hard enough the dome light will come on.

Is anyone familiar with this problem, to me it sounds like the latch needs to be adjusted.

 

I have a 98 Montero and the alarm goes off pretty often.

What I've noticed is if any remotes (Chrysler / GM vehiles mostly) is operated close to my vehicle, it sets off the alram. In one or two cases it even unlocks it.

If the car is turned off and the alarm is NOT armed, if I use my cell phone from inside my vehicle, it sets off the alarm. In a couple of instances, if I just use the button on the doors to lock and unlock the car in quick successions, it would do the same.

I'm not sure why it does that, but a possibility is that any wires in the vehicle is exposed, it would receive the signals from the remotes or any other electro magnetic waves and confuses the alarm sensors.

I have wire from the visor that is hanging out and I'm planning to trim it to the plastic and cover it with tape and put it inside the fixture to see if goes away. I will keep you posted.

 

One more thing.. I think your door problem is seperate from your alarm. The door sensor button which is on the bottom right handside on the body may have / going bad. Check that out.