Chapter 19 Installation and Troubleshooting of Domestic Refrigerators and Freezers
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Carefully review Chapters 9 through 14 before
attempting to locate trouble in electrical systems.
When checking and servicing electrical circuits, first
check the outlet electrical supply. Check the appliance
voltage specifications.
Using a voltmeter, test the open-circuit voltage.
Next, plug in the appliance and check the voltage again
while it is running. The open-circuit voltage is likely
to be slightly higher than with the motor running.
However, this difference should not be more than 5 V.
A small voltage drop between 5–10 V may be due to a
clogged condenser, fan blade imbalance, or an electrical
component that is drawing too many amps. If the unit
has a voltage drop greater than 10 V, it is usually a sign
that the compressor windings are shorted, a fan motor
is locked up, or an electrical component has shorted out.
Most refrigerators and freezers have a wiring
diagram attached to the back. Figure 19-10 shows the
various electrical circuits typically found in a domes-
tic refrigerator. Locate the appropriate wiring diagram
and check each circuit independently. If the compres-
sor fails to start, follow these steps:
1. Find out if electricity is reaching the compressor.
2. If it is, check the starting relay and circuit protectors.
See Chapter 14, Servicing Electric Motors and Controls.
3. Disconnect all wiring from the compressor.
4. Check the compressor with a manual start test
cord. Figure 19-11 shows a test cord for a typical
compressor with Start, Run, and Common
terminals. The ground clip, labeled 4, must be
fastened to the dome. The fuse is located in the
black wire of the manual start test cord.
Safety Note
Connector Insulation
All clips or connectors should be
or should have a rubber boot over them to protect the
technician from shocks.
When the start/run switch is pressed, the run cir-
cuit closes first. Then, the start circuit closes. After one
to two seconds, the switch button is lifted just enough
to open the start winding. If the motor operates cor-
rectly, the problem is in the external circuit.
A test cord like the one shown in Figure 19-12 can
be connected to a capacitor-start, induction-run motor
in order to test the motor. The capacitor in the system
being tested should be replaced by a new one of the
same voltage and microfarad rating. An extra clip wire
C onnector Insulation
A ll clips or connectors should be pplastic-coated, lastic-coated,
or should have a rubber boot over them to protect the
technician from shocks.
Refrigerator Compartment
Optional Ice Maker
System (Some Models)
Freezer Compartment
Brown
Brown
Cabinet light
White
White
Yellow
Yellow
Black
Black
Red
Red
Start
Run
C M M
S
L
S
Overload
Comp.
motor
Relay
Non-ribbed
Green/yellow
Rear
panel
Green
Yellow
Ice
maker
White
Cabinet
light
switch
Red
Red Blk Blk
Coil heater
Defrost
thermostat
White
White
White
Ribbed with
white marker
White
White
White
Water
valve
Rear
panel
White
Freezer
fan
Green
Green
Black Black
Green Green
Orange
Cold
control
Control mtg. brkt.
Motor mtg.
bracket
Green
Green
2
4
3
TM
1
Defrost
timer
Frigidaire
Figure 19-10. A wiring diagram of a typical domestic, single-door automatic defrost refrigerator with a defrost timer and freezer fan.
Note color coding of wiring to aid in tracing the circuits.