if headlight is really dim, do as Nutty Prof said and check your ground. I had a Triumph TR7 that had one headlight that wouldn't go up or down (hide away/pop up headlights), and when manually raised,, same headlight would be really dim (estimated less than half brightness). Turned out to be a bad ground (no ground, really), and fixed it fixed both problems. We were checking wiring, and I asked by buddy to check one wire (hot, got +12V). Asked him to check other wire (should have been ground), also got +12V. Second wire that I asked him to check was supposed to be a ground, so he should not have hand any voltage. Went back and forth for a while, and he jumped the ground lug of the headlight to a chassis ground with a jumper, and lo and behold, headlight got to full brightness. we traced the wire back, and it was on a post with a bunch of other ground wires with ring terminals. He took off the nut holding the ring terminals on, pulled off all of the wires, then scraped all around the bolt, and put the wires and nut back on. Headlight was fine, and it went up and down as well. Tuns out that the car, which had a Chevy 350 in it, was taken apart, the bodywork all fixed and repainted inside and out. While the person who put the car back together again had put in everything back had not miswired anything, he didn't scrape off the paint from all of the grounding points for the car, either. Other things began to work, radio had more volume, dash lights worked properly, and turn signals started to work properly as well.
We were asked to rewire the entire car. We politely, but firmly, refused.
Lessons to be learned: a) verify that a ground is actually a ground, or you will chase your tail for ever and ever; b) don't assume that whoever puts a car back together is doing things properly, no matter how high his reputation is. Its the whole Benny Hill ASSUME routine played out in the real world.
Kostas
