i am in the process of a retrofit and all the sudden the bulbs won't light up. i tested the bulbs about 4 months ago and now I'm about to install them into my headlight units. the fuse on the cabling coming off the battery is lit and my bulbs aren't lighting now. my assumption is that either one or both of my ballasts have gone bad. I'm done for the night but I'm going to further troubleshoot tomorrow and was wandering if anyone has comments before i troubleshoot more tomorrow and possibly buying new ballasts.