[KennyLee]

Ruud Heat Pump outside unit not working. Changed Contactor and Capacitor. Unit will run only if hold contactor down. Blower and heat strips work fine.

[hkstroud]

Do you have voltage (low voltage) to contactor coils?

[ma0641]

Could be a control panel, contactor or thermostat issue. You need voltage at the contactor to pull the contactor in.

[21boat]

Just to add here<br><br>possibly the Voltage to the contactor is controlled by the anti-short cycle timer switch in a small circuit board is not allowing voltage to the contactor.<br>Just to double check things use a volt meter to se e if 220volts at the incoming side of the contactor.<br>If voltage is good and you and as you said the compressor and fan motor come on set the thermostat for cool Then use the meter to check for 24 volts at the contactor solenoid terminals. If you have 24 volts new contactor. Is bad, replace contactor.<br>If you don’t have 24 volts re-set the pressure switch.<br>If the pressure switch is good check low voltage wires from the thermostat on the yellow and common (blue/black) wires for 24 volts. If there are no volts on yellow and the common either the thermostat is bad or you have a broken thermostat wire.&nbsp;<br><br><br><br>

[21boat]

Sorry I don't have a clue why my post came out messed up use to old ASK system