I have a Ducane condensing unit model HP12B30. The compressor and fan will not kick on. I thought it may have been the contractor relay so I replaced it. Even with the new relay, the unit still will not pull the contact poles down to kick on the fan and compressor. I can manually push the contact poles down and the unit will run but imediately kicks off when I release the contact poles. Any ideas?
you need 24V out at the condenser that comes from the furnace/air handler TRANSFORMER thru the thermostat setting.quick test pull the stat cover and looking at the subbase jump R to Y1 that is your condenser contactor...if you can read voltage your meter should show 24Vs on the 2 THIN brown wrapped wires coming into the condenser.if you don't have it a wire might be broke on the run out was it working and it stopped suddenly?