– 29 –
Check Valve
A nylon piston inside the check valve fl oats back
and forth, depending upon refrigerant fl ow.
The check valve prevents refrigerant from
fl owing back into the freezer evaporator.
When the main control rotates the 3-way valve
for fresh food only cooling, the check valve will
prevent refrigerant from fl owing in the freezer
evaporator (refrigerant will naturally fl ow to the
coldest area).
The check valve is only available with a new
freezer evaporator.
Caution:
Do not attempt to replace only the
check valve. The nylon piston in the check valve is
extremely heat sensitive.
•
•
•
•
Check Valve
Fresh Food Evaporator Fan
A variable speed
12-VDC motor
is mounted in
front of the fresh
food evaporator.
The fan, the
blower, and
evaporator cover
are replaced
as a complete
assembly.
When activated, the fresh food evaporator fan
recirculates the air in the fresh food compartment,
providing cooling independent of the freezer
evaporator fan.
The main control board gathers information from
the fresh food thermistors to determine when, and
at what speed, fan operation should occur.
A constant 13.6 VDC is provided to the fan from the
main control board (J2 pin 8 to J2 pin 3).
Speed is regulated by pulse width modulation on
the common side of the fan. When operating, the
common side of the circuit is pulsed open and
closed. This pulsing produces effective voltage
being received at the motor, which is equivalent to
a reduction in voltage. Fan speed is selected and
maintained by the main control board regulating
the length and frequency of the 13.6-VDC pulse.
High Speed (12 VDC measured)
Medium Speed (10 VDC measured)
Low Speed (9 VDC measured)
12 VDC
10 VDC
9 VDC
13.6 VDC
0 VDC
0 VDC
0 VDC
13.6 VDC
13.6 VDC