60 Heavy Frost on Evaporator
Disconnect power. Unplug blue connector
from main board. Measure between red
wire on connector and orange (neutral)
wire on main board J7, pin 9.
Are there approximately 37 ohms?
Always check door ajar,
customer usage -
numerous door
openings, etc.
Check wiring harness,
defrost heater, and
defrost overtemperature
thermostat.
NO
Verify thermistors are within
proper range using
thermistor values chart.
Is resistance within range?
Replace main
board.
Check wiring
connections. If
OK, replace
thermistor.
NO
YES
YES