Without Daytime Running Lamps (DRL)

Voltage is available at all times to the Headlamp Switch from the LIGHTING Maxi Fuse through the RED (42) wire. Within the Headlamp Switch is a 17A circuit breaker which resets automatically. The circuit breaker opens upon heating due to an overcurrent condition. With the circuit breaker open, current stops and the circuit breaker's thermal element cools. When sufficiently cool, the circuit breaker re-closes.

The three position Headlamp selector switch has an OFF position, a parking lamps position, and a headlamps position. When the switch is in the headlamps position, voltage is available on the YEL (10) wire to the Headlamp Dimmer Switch. The Headlamp Dimmer Switch is part of the Multifunction Switch on the Steering Column. By pulling the Multi-Function Switch lever up along the axis of the Steering Column, the switch changes selections. Repeated switch operations alternates between the high beam selection and the low beam selection.

With the low beam's selected, voltage is available on the TAN (12) wire to the low beam Connector pins (Sealed Beam Headlamps) or to the low beam headlamps (Composite Headlamps). Because the headlamps are grounded, current flows through the low beam filaments and light is emitted. The LH Sealed Beam Headlamp is grounded at Ground G201 by the DK BLU (593) BLK (150) wire.
^ The RH Sealed Beam Headlamp is grounded at Ground G109 by the BLK/WHT (151) wire.
^ The LH Low Beam Composite Headlamp is grounded at Ground G108 by the BLK (150) wire.
^ The RH Low Beam Headlamp Composite is grounded at Ground G109 by the BLK/WHT (151) wire.

With the high beam's selected, voltage is available on the LT GRN (11) wires to the high beam Connector pins (Sealed Beam Headlamps) or to the high beam headlamps (Composite Headlamps). Because the headlamps are grounded, the lamps operate.
^ The LH Sealed Beam Headlamp is grounded at Ground G201 by the DK BLU (593)1 BLK (150) wire.
^ The RH Sealed Beam Headlamp is grounded at Ground G109 by the BLK/WHT (151) wire.
^ The LH High Beam Composite Headlamp is grounded at Ground G201 by the DK/BLU (593)1 BLK (150) wire.
^ The RH High Beam Composite Headlamp is grounded at Ground G109 by the BLK/WHT (151) wire.

The LT GRN (11) wire also makes high beam voltage available at the Instrument Cluster for lighting the Blue Headlamp High Beam Indicator Lamp. Since the Instrument Cluster's lamp circuits are grounded at Ground G201 by the BLK (150) wire, the lamp lights when voltage is available.