Viking FDB451 - Drain Motor

To avoid risk of electrical shock, personal injury, or death, disconnect electrical power source to unit, unless test
procedures require power to be connected. Discharge capacitor through a resistor before attempting to service.
Ensure all ground wires are connected before certifying unit as repaired and/or operational.
WARNING!
Troubleshooting
38 ©2012 Viking Preferred Service
(Some measurements require power and others require the unit not to be powered.)
Drain Motor
The dishwasher uses a drain motor to remove
water from the tub at timed intervals during
the wash cycle. In the drain mode, voltage
between P6-4 and neutral should be 120
VAC. If voltage is measured, unplug the wires
to the drain motor and using an ohmmeter,
check for approximately 15.1 Ω ohms at the
valve. If 0 Ω ohms are read, replace the drain
pump. If readings are correct, remove pump
and check for obstructions in the drain pump
(see Drain Motor Disassembly procedure,
page 27 ).
P-10
P-6
P-6
P-10
Note: Testing the drain motor can be
achieved in the diagnostic mode.
Moisture Sensor
The dishwasher uses a moisture sensor that
is mounted in the base pan of the dishwash-
er. Any moisture that comes in contact with
the sensor
will cause the unit to stop lling, operate the
drain pump, and signal an error code. If the
sensor is open, an open fail code will sig-
nal (see Fail Codes, page 12). Resistance
between P8-1 and P8-2 should be 175K Ω
ohms.
P-8
P-8