Circuit breaker #14 applies voltage to all of the filaments of the left headlamp at all times through CKT 688 or CKT 689 (RED/YEL). Circuit breaker #15 applies voltage to all of the filaments of the right headlamp at all times through CKT 694 or CKT 695 (RED/WHT). The headlamp switch is grounded at all times through CKT 87 and CKT 86 (BLK) to G105.

In DRL operation, ground is provided to the low beam filaments through a different circuit through the normally closed contacts of the lighting relay. The park brake switch is grounded at all times at G105. When the parking brake is disengaged, ground is provided to one of the coil contacts of the DRL Off relay. The DRL Off relay is permanently grounded at G105. When the ignition switch is in the RUN position, voltage is supplied to the other coil contact of the DRL Off relay, causing the relay to energize. The ground path is now provided through the now closed contacts of the DRL Off relay through the CKT 744 (LT BLU) to the normally closed contacts of the DRL On relay. The DRL On relay is grounded through the generator connector C3 terminal B with the ignition in START and will open up its contacts when the ignition switch is in the RUN position and the engine is running. The ground path is now provided through CKT 729 (RED/BLK), through the DRL series dropping resistor, and through CKT 715 (RED/YEL) to the normally closed contacts of the lighting relay. The low beam filaments now light at 90 percent intensity because of the additional voltage drop across the DRL series dropping resistor.