Problem
No Cooling
System will not start
Compressor will not start—fan runs
Compressor and condenser fan will
not start
Evaporator fan will not start
Condenser fan will not start
12
TROUBLESHOOTING
Cause/Test Method and/or Solution
Power failure. Test voltage.
Blown fuse. Inspect fuse size and type. Replace, if needed.
Loose connection. Inspect connection. Tighten if needed.
Shorted or broken wires. Test circuits with ohmmeter. Replace if needed.
Faulty thermostat. Test continuity of thermostat and wiring. Replace, if needed.
Faulty transformer. Check control circuit with voltmeter. Replace, if needed.
Shorted or broken wires. Test circuits with ohmmeter. Replace if needed.
Shorted or open capacitor. Test capacitor.
Internal compressor overload open. Test continuity of overload.
Shorted or grounded compressor. Test motor windings.
Compressor stuck. Use test cord. Replace, if needed.
Low voltage. Test voltage.
Unbalanced power, 3PH. Test voltage.
Blown fuse. Inspect fuse size and type. Replace, if needed.
Shorted or broken wires. Test circuits with ohmmeter. Replace if needed.
Faulty thermostat. Test continuity of thermostat and wiring. Replace, if needed.
Faulty transformer. Check control circuit with voltmeter. Replace, if needed.
Faulty compressor contactor. Test continuity of coil and contacts. Replace, if needed.
Blown fuse. Inspect fuse size and type. Replace, if needed.
Loose connection. Inspect connection. Tighten if needed.
Shorted or broken wires. Test circuits with ohmmeter. Replace if needed.
Open fan overload. Test continuity of overloads.
Faulty thermostat. Test continuity of thermostat and wiring. Replace, if needed.
Shorted or open capacitor. Test capacitor.
Faulty fan relay. Test continuity of coil and contacts.
Open control circuit. Test control circuit with voltmeter.
Shorted or grounded fan motor. Test motor windings.
Shorted or broken wires. Test circuits with ohmmeter. Replace if needed.
Open fan overload. Test continuity of overloads.
Shorted or open capacitor. Test capacitor.
Faulty compressor contactor. Test continuity of coil and contacts. Replace, if needed.
Shorted or grounded fan motor. Test motor windings.
Faulty defrost control. Test control. Replace, if needed.