Ew... That sucks. My BTTF DeLorean had a similar problem with the headlights & taillights after I married the upper and lower halves together. They flickered a little bit and ceased to function entirely after I got everything tightened down. A single wire probably got pinched somewhere - no clue where. I may one day revisit it, but it was an exhausting piece of work to get it to the end and I explain it away by saying its a truly accurate replica of a DeLorean, electrical problems and everything!