Power Locks: Description and Operation

The Power Door Lock system operates to lock or to unlock all doors with the actuation of a single Door Lock Switch. Power is available at all times from the PWR ACCY Circuit Breaker through the ORN (540) wire to the Left Front Power Door Lock Switch, the Right Front Power Door Lock Switch, and the Rear Power Door Lock Switch (except cutaway models). This voltage is also supplied to the Power Door Lock Relay and the Power Door Lock Control Module. Both the relay and the module are grounded by the BLK (150) wire at Ground G201 (Except Upfitter Provisions) or Ground G201 & G200 (Upfitter Provisions).

Each of the Door Lock Cylinder rocker switches have two contacts. when the upper portion of the rocker switch is depressed to unlock the doors, one contact closes to apply voltage on the WHT (194) wire. This voltage is applied to the Unlock coil in the Power Door Lock Relay. Since the other side of the relay's coils are grounded by the BLK (150) wire at Ground G201 (Base) or at Ground G200 (Upfitter Provisions), the coil energizes when voltage is applied. Relay contacts then operate to apply voltage on the TAN (294) wire. The relay contacts are normally connected to ground. When the Unlock relay operates, it's ground connection is broken but the contacts of the Lock relay remain connected to ground. Thus voltage and grounding are applied to each Power Door Lock Actuator Motor and the motor operates in the direction required to unlock the doors.

When the lower portion of the Power Door Lock Switch is depressed to lock the doors, the other contact closes to apply voltage on the LT BLU (195) wire. This voltage is applied to the Lock coil in the Power Door Lock Relay. The Lock coil energizes and contacts operate to apply voltage on the GRY (295) wire. When the Lock relay operates, it's ground connection is broken but the contacts of the Unlock relay remain connected to ground. Again, voltage and grounding are applied to each Power Door Lock Actuator Motor and the motor operates in the direction required to lock the doors.