2000 Cadillac sts electrical issues
 

Hey Guys, I'm brand new to the forum so please go easy. I bought a 2000 Cadillac sts from with only 48k miles. It belonged to a
grandmother and she gave it to her grandson who didnt want it. Anyway car had been sitting in a garage for quite sometime.
Guy told me it has electrical issues when I bought it. So here is whats going on;
Turn key to ON everything works as it should.
Start the car? Radio goes off and makes a popping noise.
Door locks and windows will not work.
Getting all kinds of warning lights on the dash. traction control, battery, security, lights on, etc, etc
Blinker works or flashes at a mind blowing speed!!!
Getting service theft system, service stability system
The steering wheel goes up sometimes while driving?
It was throwing about 100 codes which i cleared. I unplugged the battery and checked grounds.
Can anyone help me? Anything would be greatly appreciated. Is it the RIM? The ignition switch?
This is the 3rd Caddy I have owned and it is immaculate!!! I just want it work like i know it should

Checking the grounds was good, but apparently not the issue. with can bus systems all sorts of things can happen when one or two things happen that interrupt the communications between various systems. You almost need to have a factory service manual - available for less money on disk - to find your way to the issue.

I am almost wondering if this car was in a flood.

Mark D.