LG LMVM2277ST Product Training Manual page 60

Door Interlock Switches
MONITOR SWITCH
Disconnect the wire lead from the switch.
Connect an ohmmeter to the COM (common) and NC
(normally closed) terminals of the switch.
With the door open, the meter should indicate a closed
circuit.
Closing the door should indicate an open circuit.
(See chart, next slide.)
T-20
LMVM2277ST
60