a-c dont work on 1998 Chevrolet 3500 Pickup

i dont seem to have power to the clutch or high pressure switch. the control inside shows the the ac is on, but nothing seemd to have power undr the hood. all fuses are good, just want to know if there is anything other than the controls on the inside of the cab that could cause this problem.

The A/C system may be low on refrigerant charge, this will case the pressure cycling switch on the side of the accumulator to turn the system off. Check for power at the pressure cycling switch. Also check refrigerant pressure in the system.
thanks, it was the instrument control head in the dash,