headlight not working

[CALIMAX]

I have a 2002 2500HD cc/sb D/A. My right low beam headlight is not working and neither are my driving lights. When checking voltage at the headlight socket ti shows both pins have voltage. The only thing I can think of is I lost my ground somewhere. Does anyone know where GM grounds the right headlight? Why would I have voltage on both pins of the socket.
Thanks, Ken

[madmatt]

your headlights all use the same ground. if you had a bad ground none of your headlights would work. w/ your head lights on you should have power to one pin in both you low and high sockets. the dimmer switch provides the ground to the selected circuit, low or high. sounds like you have a short to power in your ground circuit which should be the yellow wire in the "B" jack of the low beam connector. If this is the case the circuit must be interrupted somewhere or it would affect the left side as well since the circuits interconnect. Have you tried new bulbs in the driving lights or tested them any. from the diagrams, it doesn't look like the problems could be related unless the two circuits are shorted together.

[CALIMAX]

I have tried a new headlight bulb but not the driving light. The filamants in the driving lights appeared to be ok but I will double check today. Why wouldn't the fuse blow if there is a short in the headlight wire. The grouned wire on the left headlight appears to be the purple wire.
Thanks, Ken

[madmatt]

if it's a short to power, it won't blow the fuse in the headlight circuit because it's the circuit providing the ground. check for other blown fuses in other circuits. also ppl is the high beam ground and yellow is the low beam ground. your supply should be orange to all headlamps.