Amana GPCM3 Series Service And Troubleshooting page 48

Troubleshooting
Is there 24v
No
between C & Y2 at
thermostat?
Yes
Is there 24v at
No
compressor
contactor relay
coil?
Yes
Are relay
No
contacts closed?
Should read 0v at
pins 2 & 4
Yes
Is there 18-28vdc
at compressor
unloader plug
harness?
Yes
Does compressor
change from part load
to full load? Verified
by amp draw
Yes
Does blower
change to 2nd
stage cooling
speed?
Yes
Are refrigerant
pressures and
superheat/subcooling
correct
Yes
48
No
No
24v between C &
No
No
T 1/2/3/4/5 at
motor harness?
Yes
Check for
Check for
No
No
leak in
restriction in
refrigerant
system
system
Yes
No
Yes
Check for restriction
or defective TXV
Repair Leak
Heat Pump - Cooling (2 Stage)
Check thermostat & wiring
Check thermostat & wiring
Replace relay
Replace unloader plug
Replace compressor
Check thermostat and wiring or
motor controller
Check blower motor
Verify refrigerant charge
Pressure test, evacuate and
recharge system
Pressure test, evacuate and
recharge system
Second stage cooling operating