© 2010 Viking Preferred Service
45
Service Diagnostics and Procedures
Control Board Diagnosis
Testing Fan Motor (continued)
the red wire at the line break relay. The resistance
should be approximately 100
Ω
. Likewise, the
reverse
direction can be measured by reading
resistance between the yellow/white wire in the
Molex plug and the red wire at the line break relay.
Resistance should be approximately 100
Ω
. If
either or both readings are not as shown, replace
the convection fan motor
(follow convection fan
disassembly procedure)
.
Door Lock Assembly
The door lock motor is a 240 VAC motor. One side
of the motor is wired to directly to L2 (Red wire). L1
power to the lock motor is connected on the P12
connector (DL) on the main control board. Incoming
L1 Power from the main terminal block is also
connected to the P12 Connector (L1). When the
relay energizes, L1 power is sent to the lock motor.
The photo below shows the P12 connector.
There are three micro switches mounted on the
door lock assembly. One switch is not used on this
model. The photo below shows the latch assembly
lifted upwards to expose the switch positioning.
When the door is in the unlocked position, the
cam is depressing the S1 switch plunger. The N.O.
switch contact is closed and a completed circuit
is made at the P15 connection between the light
brown wire and blue/white. This signals the board
that the door is unlocked.
S2 is also N.O. and is open when the door is
unlocked. When the lock motor is activated and
begins to lock, the S1 contact opens. When the
plunger catches the door liner and pulls inwards,
the S2 switch plunger is actuated. The switch
contact is closed and a completed circuit is made at
the P15 connection between the light brown wire
and orange. This signals the board that the door is
locked.
When it is time to unlock the door, power is sent to
the door lock motor and it continues its rotation.
The plunger releases the door liner and opens the
contact on S2. When the door is fully opened, S1 is
closed by the motor cam. This will signal the board
that the door is unlocked.
Testing Lock Motor
With the Molex connector removed from the P12
board connection, use an Ohm meter to measure
resistance between black/white wire in the Molex
plug and the red wire at line break relay. The
resistance should be approximately 12.3K
Ω
. If no
resistance is read, remove the latch motor to repair/
replace
(follow latch motor disassembly procedure)
.
Testing Latch Switches
To check the latch switches, access the control
board and unplug the P15 Molex plug. With the
door in the unlocked position you should read
continuity between the light brown wire and the
blue/white wire and zero
Ω
between the light
brown wire and the blue/white. If your readings are
incorrect or reversed, remove the latch and inspect,
repair/replace
(follow latch motor disassembly
procedure).
S1
S1
S2
Not used
P15
