The Daytime Running Lamps (DRL) control module is designed to automatically operate the exterior lights, depending on the outside light conditions. The DRL control module operates in 2 modes:

The DRL control module operates in the night mode when the DRL ambient light sensor senses darkness. When this happens, the night mode contacts close and voltage is applied to the headlamps and other exterior lights through the same circuit path as when the headlamp switch is in the HEAD position.

The DRL module turns off the headlamps when the engine stalls with the DRL in the night mode. The marker, park and tail lamps are on while the engine is being cranked. The headlamp switch operates as usual.

The DRL ambient light sensor is a light sensitive variable resistor. The DRL ambient light sensor decreases in resistance as outside light intensity increases. The DRL control module measures the voltage drop across the DRL ambient light sensor. The DRL control module then determines whether the day mode or the night mode should be in operation.

The DRL control module will not operate any headlamps or exterior lamps if the park brake is applied before the ignition switch is turned to RUN. This allows the operator to start the vehicle and keep the headlamps off as long as the park brake is applied. The DRL control module will activate the headlamps when the park brake is released with the ignition switch in RUN.

The park brake input feature will only function when the park brake is applied before the ignition switch is turned to RUN. The headlamps will not turn off if the park brake is applied after the ignition switch is turned to RUN.

Whenever the park lamps are on, voltage is applied from the FRT PARK LPS fuse through circuit 9 to the underhood accessory wiring junction block. The voltage is then sent to both the front side marker lamps and the front park lamps.

Voltage is applied at all times from the LP PARK fuse to the headlamp switch and the Daytime Running Lamps (DRL) control module through circuit 1340. Voltage is applied to circuit 74 when the headlamp switch is in the PARK or the HEAD position. Current flows through circuit 74 to the TAIL LAMP fuse through circuit 301. Voltage then flows to all rear park, rear side marker, tail and license plate lamps, turning then on.

Voltage is applied from the TURN SIGNALS fuse to the normally closed pole of the hazard switch in the turn signal switch when the ignition is in the RUN, BULB TEST or the START position. The voltage then flows through circuit 539, which feeds the hazard lamp/turn signal lamp flasher through circuit 1508. With the turn signal switch in the turn left position, voltage is applied through 2 circuits. Voltage flows through the turn signal switch circuit 1414 at terminal A13 of harness connector C201 and circuit 18 at terminal E10 of C201.

For circuit 1414, voltage flows through circuit 1414 to the instrument cluster for the left turn telltale, and to the daytime running lamps control module. Voltage then flows through circuit 14 to the underhood accessory wiring junction block to the left front turn signal lamp.

For circuit 18, voltage flows through circuit 18 to the left rear turn signal lamp. Current flow heats the timing element in the hazard lamp/turn signal flasher. The timing element continuously opens and closes the circuit for the right turn signal lamps, circuit 1415 terminal A12 of C201 and circuit 19 terminal E11 of C201.

Voltage is applied when the ignition is in the RUN, BULB TEST or START position through the TURN SIGNAL Fuse in the fuse block, to the turn signal switch through circuit 539. When the turn signal switch is placed in the TURN LEFT position, voltage is applied through the closed contacts of the turn signal switch, to the LH cornering lamps through circuit 57. The LH cornering lamps are grounded through circuit 57. The LH cornering lamps are grounded through circuit 1350 to G101. When the turn signal switch is placed in the TURN RIGHT position, voltage is applied through the closed contacts of the turn signal switch, to the RH cornering lamps through circuit 58. The RH cornering lamps are grounded through circuit 1250 to G102.

Voltage is applied at all times from the HAZARD fuse to the normally open poles of the hazard switch in the turn signal switch through circuit 1840. The hazard lamp/turn signal lamp flasher receives voltage through circuit 1508 when the hazard switch is in the HAZARD position. The current flow heats the timing element in the hazard lamp/turn signal lamp flasher. The voltage continuously opens and closes circuit 16 to the turn signal switch and then to all the turn signal lamps and both of the turn telltale lamps. All of the turn signal lamps and both of the turn telltale lamps flash on and off.

Voltage is applied at all times from the STOP LAMPS fuse to the stop lamp switch through circuit 140. Voltage is applied from the stop lamp switch to the turn signal switch through circuit 17 when the brake pedal is depressed. The voltage turns on the left and the right tail/stop/turn signal lamps and the center high mounted stop lamp.