Headlamp: Description and Operation

Voltage is applied at all times to the Headlamp Relay, Headlamp Switch, and the Headlamp Retractor. With the Headlamp Switch turned to the HEAD position, the Headlamp Relay coil is supplied with a ground. The contacts of the Headlamp Relay close, allowing current to flow from the HEAD fuse through the Headlamp Relay to the Dimmer Relay and then to the low beam filament of the Dual Beam Headlamps.

The Dimmer Relay switches the power from the Lo-Beam to the Hi-Beam or Hi-Beam to Lo-Beam and is controlled by the Turn Switch. The beam can be switched by pulling back on the Dimmer Switch.

In GT or LX vehicles equipped with VMM or system scanner, current flows through the Dimmer Relay to the Headlamp Checker, and then to the Headlamps. The Headlamp Checker determines if there is a lamp outage and signals a warning to the driver.

Headlamps Relays

Voltage is also applied at all times to the coil of the internal relay. The internal relay contacts will close (position 1) allowing current from the HEAD fuse to flow through the Headlamp Retractor mechanical switch and relays. The Headlamp Retractor relays are permanently grounded through G101 and G102, the relays are energized and their contacts are pulled closed as soon as current is supplied. With the Headlamp Retractor relays energized and their contacts closed, current is supplied to the Headlamp Retractor motor form the RETRA fuse. As the Headlamps reach their full UP position, the mechanical switch each Headlamp Retractor moves to position B and opens the circuit between the Headlamp switch internal relay and Headlamp Retractor relays. With current no longer supplied, the Headlamp retractor relays are de-energized, their contacts opens, the circuits from the RETRA fuse open, and the motors stop operating.

Headlamp Retractor

The Headlamp Retractor motor always rotates in the same direction. A cam assembly attached to the motor shaft moves the Headlamps into their UP or DOWN positions. When the Headlamp Switch is turned to PARK or OFF position, the ground is removed from the Headlamp Internal Relay. The Headlamp Internal Relay will de-energized and its contact will switch to position 2. Current is now supplied to the Headlamp Retractors Relays through the HEAD fuse, Position 2 of the Internal Relay contacts, and the DOWN side of the Headlamp Retractor switches. This action energizes the Headlamp Retractor relays, pulls the contacts closed and closes the circuits between the RETRA fuse and the Headlamp Retractor motors. The motors continue to operate until the Headlamps reache their full DOWN position and the mechanical switches in the Headlamp Retractors opens.

Flash-to-Pass

Flash-to-Pass can be operated with the Headlamp Switch in the OFF position and the Retractor in the DOWN position. This is done by pulling back on the Dimmer Switch. This will close the Headlamp Relay and apply voltage to the Headlamp Retractors. The times of the Dimmer Switch will continue to apply voltage to the Headlamp Retractors, to maintain the Headlamps in the UP position to allow flashing of the Headlamps without lowering the Retractors between flashes