Underhood Lamp: Description and Operation

Circuit M1 from the Power Distribution Center (PDC) supplies battery voltage for the underhood lamp. The underhood lamp portion of circuit M1 has a case-grounded mercury switch in series after the lamp. When the hood is raised, mercury inside the switch moves to a position where it connects circuit M1 to ground, illuminating the lamp.

The underhood lamp is wired in parallel with other components on circuit M1.