Heavy Frost On Evaporator (Diagnostic Chart) - GE PSC21MGM Technical Service Manual

Run Service Diagnostic Test (1-4)
Defrost system check
Does defrost heater come on?
No
Carefully unplug J9 blue connector from
main board. Measure between blue wire on
connector and neutral orange wire on main
board J7. Is there approximately 27Ω?
No
Check wiring harness
Check defrost heater
Check defrost thermostat
Caution: Unplug power when disconnecting and
connecting connectors on the board.
Heavy Frost on Evaporator
Check door ajar
Yes Customer usage -
numerous door openings
Check for 120 VAC from
neutral orange wire J7 to
Yes defrost terminal J9 on main
board.
Is 120 VAC present?
No
Run Service Diagnostic Test (0-7)
for thermistors
Do thermistors pass test?
No
Repair wiring connections
or
replace thermistor
– 52 –
Reinstall blue connector
Measure for 120VAC
Yes
at defrost heater.
Is 120VAC present?
No
Check wiring
between heater
and main board
Replace
Yes
main board
Replace
Yes defrost
heater