OK, I wanted to update my front 4 headlights in my 1965 Plymouth Sport Fury. The lights that came with the car were old, 1 was burnt out, and I just wanted a newer look with the LED halo circle. After I finally got them all installed, I tried them out, the worked and looked great, for about 1 minute. With high-beams and low beams on, they dimmed and eventually fizzed out. I placed a volt meter on the light circuit and found, when initially turned on, I was only getting about 10v at the front lighting harness. As they stayed on, the voltage dropped to about 8.3 or so, then they fizzled out, with voltage bouncing all over. I read elsewhere on these forums that the dash light switch and floor dimmers were high-draw devices, and if suspected, should be replaced, which I did. That did totally improve the situation, but not completely. Now, low-beams only, voltage reads about 11v up front, and they stay on as long as I want. However, turn on the highs also, and it lasts longer than before, maybe 3 minutes, but then the voltage drops, and once below about 8V or so, they fizzle and dim out. If I put hit the floor dimmer switch and go back to low-beams only, the highs go out as they should, the lows stay on, and it's all good. Ideas???