Troubleshooting
16
©2012 Viking Preferred Service
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.
Door Lock Assembly
The door lock motor is a 240 VAC motor. One side of
the motor is wired directly to L2 (red wire). L1 power to
the lock motor is connected on the P12 connector (DL)
on the main control board. When the relay energizes, L1
power is sent to the lock motor. The photo below shows
the P12 connector.
There are three microswitches mounted on the door lock
assembly. One switch is not used on this model.
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 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 the P15 connection between the brown
and orange wires. 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 ohmeter to measure resistance
between the red wire (L2) on the line break relay and
the black/white wire at P12. The resistance should be
approximately 12.5K ohms. If no resistance is read,
remove the latch motor to repair/replace (Follow the
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 (0 ohms)
between the brown wire and the blue/white wires, and
read infinite ohms (∞) between the brown and orange
wires. If your readings are incorrect or reversed, remove
the latch and inspect, repair/replace (follow latch motor
disassembly procedure).