is your new light an LED? if it is start by trying switching the wires because LEDs have to have a specific wire on positive and negative (if youve already done this, sorry, i always like to start simple)
where are you testing the voltage coming through? i havent actually pulled the wires apart, but i saw it and it looked like there were just normal crimp on connectors, maybe one is loose and it just so happened it was connected when you had the volt meter hooked up
one more thing to try is one more bulb, id take the stock one to radio shack and have them see if they can match it
good luck and congrats on gettin your VX