2001 Impala LS squealing

First off, I have a 2001 impala LS with 120,000 on it. Recently the steering column, and the catalytic converter were fixed at the dealer.Last night we pulled into our driveway and the car started squealing. It was definately coming from under the hood, but it stopped when the AC was turned off. My wife told me that it also started while the AC was turned off today. It sounded like a fan hitting something. The next day we went to go check the car to see what the noise was, but when the key was turned the radio and the instrument panel went crazy. Lights were going on and off, the radio was fuzzing, and the alarm was trying to go off, but it was muffled. It was like my car was possessed by the devil. Car has had passlock problems before, but not like this. Think they are related? We need to figure this one out quick as our other car is having tranny problems that nobody can seem to figure out. Any ideas are welcome. Thanks in advance for any help.