This is a duo derm roof top air conditioner, possible compressor freezing up

Hi,
Sounds like the compressor is toast...if the caps have been changed and there is voltage there, you have done all you can...replace the compressor or buy new...

heatman101

Trace the wires from the compressor back to where they come from. They should be coming from a contactor or from the circuit board. It's possible the relay is built into the circuit board (it will look like a little black box on the board. Let me know what you find.

how old is unit and does it have refrigerant in it

maybe the capacitor for fan was already busted try to check that.

It sounds like the compressor is locked up. You can try a start boost or hard start kit but once this starts the compressor is on it's way out.

when the cmpressor freeze up. unless you have some machenic know how, it is pretty much useless to anyone. even you can rebuild it. the cost for the parts is more than a new one.

yes , this can happen if it sets to long , thats why even cars pumps are engaged when even the heat is turned on , to keep the compressor from siezing up

Sounds like 1 of 3. Blower motor capacitor, relay or thermostat. Try to run fan only if that is an option and see.