Heat Controller BG-103A Service Manual page 21

Check power source.
Check control switch
setting.
Only compressor fails to
start.
Drop in power voltage.
Defective compressor
capacitor.
Check capacitor.
Replacement.
Irregular motor resistance ( )
Irregular motor insulation ( )
Replacement of compressor
(Motor damaged)
Fails to Start
Improper thermostat setting
Loose terminal connection.
Improper wiring
—21—
Check circuit breaker
and fuse.
Gas leakage at feeler bulb
of thermostat
Check control switch.
Only fan fails to start.
Improper wiring.
Defect of fan motor
capacitor.
Irregular motor resistance
( ).
Irregular motor insulation
( ).
Replacement of fan motor
Regular but fails to start
Replacement of compressor
(locking of rotor, metal)