Map light switch

Map light has +12v on one side of the lamp always!

The door switch's when activated provide a ground to the lamp through the map lamp switch as shown previously. The switch has 2 posts. When the switch is down the 2 posts are connected together and allow the ground from the door switch to pass through to the lamp. When the switch is up it directly connects the lamp side to ground. This can be a battery killer as previously mentioned. This is the way the factory did it!

Not all cars had the switch! Some just had the lamp and it turned on an off with the door switch's just like the dome lamp or c-pillar lamp for barracuda's.