Goodman Condensing Unit GSX130421A

Check for 24 volts at thermostat wires C and Y in the condensing unit control panel

Is there voltage at thermostat wires C and Y?

Check the continuity of the thermostat and wiring

Set fan selector switch at thermostat to 'ON' position

Check for 24 volts at wires C and G

Is there voltage at wires C and G?

Check the continuity of the thermostat and wiring

Disconnect ALL power before servicing

Connect voltmeter to lugs (L2) and (C)

Is the power ON and call for cool or heat pump provided to energize the on-board compressor contactor/relay?

Measure voltage across on-board compressor contactor/relay contacts

Ensure all open flames are extinguished

Turn off electrical power and other heat sources

Verify that the following components are properly in place and secured

Was the hermetic system properly evacuated during manufacture and servicing?

Disconnect all power sources before servicing or installing

Disconnect power to the air conditioner or heat pump

Disconnect the sensor from the unitary (UC) control

Connect an ohmmeter across the sensor terminals and record the resistance

Is the sensor within the valid resistance range (10kΩ, +/-10%)?

Replace the sensor if it is open, shorted, or outside the valid resistance range

Disconnect ALL power sources before servicing or installing.

Ensure multiple power sources are checked and disconnected.

Remove unit wiring from disconnect switch.

Wire a test cord to the disconnect switch.

Ensure the protective terminal cover is in place.

Connect the three leads to the compressor terminals at the nearest point to the compressor.