© 2010 Viking Preferred Service
43
Service Diagnostics and Procedures
Relay Board Diagnosis
Door Lock Assembly
The door lock motor is a 120 VAC motor. One side
of the motor is wired directly to the main neutral
terminal block. L2 Power (red) at the K1 relay (relay
board) supplies power to the lock motor when the
relay is energized.
When the door is required to lock or unlock, the K1
relay energizes and sends line voltage to the door
lock motor.
The position of the door lock motor is monitored
by the S1 and S2 door interlock switches connected
to PL2 (lower oven) and PU2 (upper oven) shown
above.
There are three switches mounted on the door lock
assembly. S1, S2 and the door interlock switch. The
photo above shows the location of the switches.
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 PL2 (lower oven) and PU2 (upper
oven) connection between the light brown and
blue/white wires. 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
PL2 (lower oven) and PU2 (upper oven) connection
between the light brown and orange wires. This
signals the board that the door is locked. When
it is in 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 Latch Switches
To check the latch switches, access the relay board
and unplug the PL2 (lower oven) or PU2 (upper
oven) 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
(0)
1
between the light brown wire and the blue/
white. If your readings are incorrect or reversed,
remove the latch and inspect, repair/replace
(see
Door Lock assembly, page 56)
.
Testing Lock Motor
With the Molex connector removed from the P2
on the relay board connection, use an Ohmmeter
to measure resistance between black/white wire in
the Molex plug and the neutral terminal block. The
resistance should be approximately 2.4K
1
. If no
resistance is read, remove the latch motor to repair
or replace as necessary
(see Door Lock assembly,
page 56)
.
K1
LED
S1
S1
S2
Door Interlock
PU2
PL2