2002 Cadillac DTS cadillac dts

I'm start by checking all the fuses first with a test light or a meter. It sounds like there's a problem with either the gauge cluster or the ECM. The gauge cluster is part of the antitheft on that car

have checked multiple fuses all are good still getting power to the steering wheel seats, side mirrors. let me mention the night before after leaving work I noticed the rear view mirror onstar light glowing green it cut off after sitting in the driveway which I do not have I don't think a bit the next day start the car headed to work and trying to adjust the driver settings never seems to hold mind just bout this car bout a week ago. the person I bout it from keeps promising the original deck which the car is without none at all in the console so I pushed the harness to the side in frustration and that's when it happen
the key was locked in the ignition but able to pull it out but now I noticed the ignition turns to all the way to start position without key. no power locks or lights and the key less entry trunk alarm doe's not work. Plenty of power for the seats side mirror and steering wheel

Ok. There's the problem. Disconnect the negative side of the battery, and pulled that harness out and look for broken or frayed wires or any evidence of tampering. That needs to be repaired because it can cause damage to the computers in the car

there's the harness a some type of cable wire not the antenna spliced with silver fibers then within is red green white and black small wires and extra
speaker wires for a after market deck and a red wire with that.