Courtesy Lamp: Description and Operation

CIRCUIT OPERATION
Circuit M11 from the interior lamp defeat switch supplies power to the right and left door courtesy lamps, front dome and reading lamps, and the rear dome and reading lamps. Circuit M11 also powers circuit M1 which feeds the following lamps
- Front and rear dome lamps (without reading lamps)
- Side door courtesy lamps

The ground path for the lamps is provided in two different ways.

One way is through the case grounded door ajar switches. Circuit M2 connects to all the door jamb switches from the dome lamp. When a door is opened, the plunger in the switch closes, completing a path to ground.

The second ground path is through the headlamp switch. Circuit M2 is spliced in with the door ajar switches. When the operator turns the headlamp switch to the dome lamp ON position, a ground path is provided through the case grounded switch.

Additionally, when a reading lamp is switched ON at the lamp, the case grounded switch connects the lamp to ground.