Cadillac Repair: electrical problem, speedometer needle, cadillac seville

Question
i have a 1988 cadillac seville. everything inside the car is electrical. the problem i have is that i cant see the speed im going my gas gage i cant turn on the AC cant use the heater etc. because every thing is electric. i dont know why but somtimes when its really hot it turns on but sooner or later turns off and sometimes it just flickers on and off.i think some type o computer or module is blown out. can you please help me. can you tell me the thing thats wrong.  

Answer
Most likely a BCM computer fault. However, I can provide diagnostic and pictures to follow to diagnose the fault. E-mail me at: onlineautohelp@msn.com

Does your speedometer have the speedometer needle as in the older vehicles or is it a digital dispaly ?.