The headlamp switch is located in the instrument panel, outboard of the steering column. It closes a path to ground for the central timer module (ctm) when the park or head lamps are on and the driver door ajar switch is closed (driver door is open). The headlamp switch opens the ground path when the headlamp switch is turned off. The ground path is also opened when the driver door ajar switch is open (driver door is closed).
The headlamp switch cannot be repaired and, if faulty or damaged, it must be replaced. Refer to headlamp switch in the removal and installation section of group 8e - instrument panel systems for the service procedures.