98 Grand Am GT
 

I have a 98 Grand Am and when I drive, the airbag and seatbelt light stays on. While driving, the theft sys light will go on and off, the rpm and temp gages will fluctuate, and indicator lights go on and off. I had an aftermarket alarm installed in 2002. Took car to dealer, they said water was getting in the car causing corrosion. They replaced the dashboard cluster, but the problem continues. Even worse, the power locks have failed since I got the car back. The dealer will not even look at it. Can anybody diagnose this?