Need Cadillac Help

I have a 1991 Cadillac Seville, Went over to Iraq for 8 months came home and lost all Trip Computer Funtions/ Heating and Cooling Funtions, Check Engine Light on , All controls are blank. Ran Self Diag Test and found that Im getting lost data to any computers. BCM . etc. I dont have $2,000 to pay dealer to chase problem. I see its a common problem but no one ever posts what they went through to fix. Is it a short, bad ground, BCM ????? dont know where to start without replacing expensive parts.
Your help would be appreciated.
rich [email protected]

Post this to the appropriate Cadillac forum and the good people here will offer you lots of help. You gotta read the "stickys."

Glad you are home safe. Good luck with the car.