Headlight Doors

CIRCUIT OPERATION

Voltage to open the Headlamp Doors and to power the solid state circuitry is applied to the Headlight Doors Module at all times at terminals "B" and "E" of C1. When the Headlights are turned "ON," voltage is applied to terminal "A" of C1 as a request for the Headlamp Doors to open.

When the Headlights are turned "ON," ground is applied to the relay coil within the Headlight Doors Module. The relay contacts close and voltage is applied to the Headlamp Door Motor Assemblies. Ground is provided for the motors through the solid state circuitry until the Headlamp Doors are open. The ground circuit for each Headlamp Door Motor is rapidly switched within the Headlight Doors Module between a ground potential and a high impedance sense input. This input monitors for a fully open Headlamp Door and will allow ground to be provided until open or up to 6 seconds. A difficult to open or obstructed door will be sensed as fully open and ground will be removed by the module.

When the Headlights are turned "OFF," the ground to the relay coil within the module is removed. The contacts then return to the normally closed position which switches power and ground to the Headlamp Door Motors. The Headlamp Door Motors run in the opposite direction to close the Headlamp Doors. The ground circuit operation within the module is the same during the closing sequence as during the opening sequence.