Doing some Xenon work here and I have questions---The Bulb was out and replaced it---Didnt work,,So Im thinking Ballast ---Ive been into Xenons quite a bit---But ???? What is the igniter? and what does it do ----Is there anything else that would cause a bulb not to burn ???----Asking before I shell out 270.00 !!!!!! Actually a friends car but I may have to take one of mine out to get him on the road ---