The Door Unlock Function
When a door lock control switch is moved into the unlock position, the door lock switch grounds the unlock circuit input to the GEM. The GEM then provides 12 volts to the opposite side (relative to locking the door) of the door lock actuator(s) contained in the door latch assembly and simultaneously grounds the other side of the door lock actuator(s). This completes the door lock actuator circuit, causing the door lock actuator(s) to rotate a cam assembly in the opposite direction, which then unlocks the door(s).