Contour Enthusiasts Group Archives Forums General General Question for electrical guru's

Footwell lights are switched on ground side, not +ve side. With door closed, light off, both sides of bulb will read +12 volts to ground. With light on, only the power side of bulb will read volts, the otherside will be grounded.

I am interpreting your post to mean you want underbody lights to act as puddle lights with door open but also to work as parking lights from headlight switch. To avoid backfeeds in circuitry you will need a diode and/or an isolating relay to be installed depending on car circuits.

I'll keep an eye for a further post if you require additional info/assistance.

Note: without backfeed protection you would have parking lights on with door open and footwell on with parking lights. BTW I believe in your model year dimmer switch was changed to also work footwell lights with door closed, correct?