1970 Roadrunner. Has anyone had the high beam head lights dimmer than the low beams? When I turn on the 2 low beam headlights, they are what appears to be of normal brightness. When the high beam switch is used all 4 lights are dim. The total low beam output is much brighter than the 4 high beam lamp output. All 4 lamps have less than 100 hours of use and are regular incandescent lamps from NAPA. I am guessing the dimmer switch is going bad (original) . Are there other things to look for that might do this? Thank you