Freezer Thermistor; Defrost Heater - Viking VDSC367 Service Notebook

Disassembly
To avoid risk of electrical shock, personal injury, or death, disconnect electrical power source to unit, unless
test procedures require power to be connected. Ensure all ground wires are connected before certifying unit as
repaired and/or operational.
5. Disconnect wiring, and repair/replace
freezer fan.
6. Reverse procedure to reinstall.

Freezer Thermistor

The freezer uses the same thermistor as
does the fresh food section however, the
freezer thermistor controls the cycle of
the compressor. As the temperature in the
compartment changes, the resistance in
this device changes. These changes are
measured by the low voltage board, and
controls the operation of the compressor,
condenser, and freezer evaporator fan.
Refer to the thermistor chart on page 11.
To access the freezer thermistor:
1. Remove drawers and shelves.
2. Remove screws securing the thermistor.
26
! WARNING
Evaporator Fan
Freezer thermistor
3. Pull thermistor into freezer cabinet,
disconnect wiring, repair/replace
thermistor.
Freezer thermistor
4. Reverse procedure to reinstall.

Defrost Heater

The unit use a heater to help remove ice
build up during the defrost cycle. When the
defrost terminator closes, voltage is supplied
to the heater via the control board. With the
main power switch OFF, the defrost Heater
can be tested by removing the orange wire
off of terminal E6 on the HV board. Using
an ohm meter, check the brown wire and
Neutral and you should read approximately
30 Ω. During the defrost cycle Line voltage
passes through the Defrost Terminator the
into terminal E5 (orange wire). With the
defrost heater relay activated, the voltage
©2012 Viking Preferred Service