Door Locks: Description and Operation

Voltage is present at the Left Front Door Lock Switch at all times through the ROOM Fuse. Voltage is present at the Door Lock/Unlock Relay contacts at all times through the DOOR LOCK Fuse.

When the Left Front Door Lock Switch is moved to the UNLOCK position, voltage is applied to the solid-state component inside the Door Lock/Unlock Relay through circuit 435 (DG/O). The solid-state component momentarily energizes the coil of relay "A" and the contacts close. Current flows through the DOOR LOCK Fuse, the contacts of relay "A" (energized), circuit 432 (DG), the Door Lock Motors, circuit 432 (R) and the contacts of relay "B" (deenergized) to ground. The Door Lock Motors run to unlock all doors. As each Motor reaches the unlock position, a set of contacts inside the Motor moves to block further current flow through the Motor; the Motor stops running.

When the Left Front Door Lock Switch is moved to the LOCK position, relay "B" is energized, relay "A" remains deenergized, and current flows through the Door Lock Motors in the opposite direction. The Motors run to lock the doors.