DRL/High Beam Telltale Logic Operation

The DRL and High Beam Telltale lamps are controlled by a logic circuit contained within the cluster. The system includes circuit 1200E which is connected between the right and left high beam headlights through circuit 1200C. The logic monitors the voltage on circuit 1200E to determine the status of the telltales according to the chart shown.

To diagnose this system, measure the voltage at terminal "N" of the black 18-way I/P cluster connector. Since the high beam bulbs are connected in series during DRL operation, the voltage expected on circuit 1200E is approximately one half of ignition voltage. If the voltage drop across the left and right high beam bulbs are not closely matched, the DRL telltale may flicker or become inoperative.

IMPORTANT:
The Daytime Running Light mode will not operate if the left high beam circuit is opened and then reconnected (bulb removed and replaced) while ignition is "ON." To resume DRL mode, cycle the ignition switch.