93 Blazer A/C Doesn't Work

:banghead: Absolutely none of the A/C components work. The heater doesn't work either. The Controls in the Dash will not come on. We were told it was due to a bad relay. So we changed the relays on the plate behind the glove box back in the dash and nothing. We changed the control panel itself as well and still nothing. Does anyone have any ideas or possibly a solution?

does it have good vacuum to it?
Fuses and power feeds good?