Arming the factory installed alarm???

I have a factory installed alarm in my 95 Riviera. It was working before but I guess one of the mechanics disarmed it. Do you know how to arm it?

thank you

I would say open up ur car, put down the window, lock it up, and close it. Then, reach in with ur hand and unlock it, then open it up. If your horn doesnt go off, then your alarm IS indeed off. My guess is that it is still good to go though. I don't see why a mechanic would "disarm" it. If it is off id imagine he pulled a wire or something, I've never heard of anything with the factory alarm. May want to check ur owners manual though.

When I bought the car, it came without the alarm remote. When you lock the door with central system (using the button on one of the doors), alarm is armed. The strange thing is if you open without the remote, just using the key, it starts the alarm, only way to stop this sound is to open also the other door with the key. I took my car to couple of mechanics for other problems, and when they lock the car from one of the doors, and try to open it with the key, they all confused about how to stop the alarm sound (they basically dont know it). I guess one of them could not figure it out and cut some cables to stop it and did not fix later. But I bought a remote from ebay and want my alarm back. Any ideas?? manual does not say anything.

Ah, i understand your situation a bit better now. Looks like youre going to have to find out what wires he cut and reconnect them.

There are no wires to cut on the factory alarm. It is hooked up to the horn and BCM. The only way to arm it is from either the remote or locking either door with the door open then close it. After 30 sec. it will arm. So, if you have a window down and reach in to open the car, it should go off. To disarm, you need to put your key into either door lock and unlock it. You stated that this is not how it worked before which leads me to believe me you were already having problems. Most of the time the wires in the door boot break so I would check there.