1989 399-E heater quit on me yesterday. None of the switches will turn anything on. Checked out all the fuses & the two in the relay section and are OK. Seems like an electrical problem. where do I go next. I would Estimate parts on heater motor or controls $250-300 plus installation. what should I check before giving up on this car?

Car also needs new water pump,tensioner,a/c compressor.
I'm ready to think about a change. Owned car for 4 years, rebuilt head last xmas but it runs ok. Too much for a rough car with 210K on it .

suggestions?