1994 eldorado, heater stays on-gauges off

Hello. New to the forum here. On my 1994 Eldorado, after starting, the heater comes on, can't turn it off. Also, the gauges don't work, and the radio comes on, with no lights on it. Is this a case of demonic possesion, or can someone tell me where to start? Any help would be greatly appreciated.

I suggest to check for blown fuses to start with. It sounds like you may have a data line failure,a blown fuse is the best thing to hope for. Check for codes by pressing off and warmer on climate control for 5 sec. and re-post.