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
High Beam Ideas
- Thread starter rm6p
- Start date
mac
What ?
first thing i would do is check the grounds of the headlights on the radiator support. then check for proper voltage with lights on with car running (13.5 -14.5 volts).
Ranger
Well-Known Member
I think the dimmer switch either works or it doesn't. That would be my last suspect.
quikbird
Well-Known Member
I agree on the grounds. also these old cars were never that bright to start with. dan stern lighting has a lot of info on his website on this subject of how to get better headlights.
Coyote
Well-Known Member
Thank you quickbird, the radiator core ground is clean. When I replaced the battery a few months ago I cleaned up the ground contact and terminal to like new. The terminal is in great shape with zero corrosion. While searching websites I have seen another ground closer to the head light sockets. Is there an additional ground in that harness I am not seeing on mine? Just looked at the Daniel Stern website you mentioned. There is a lot of good stuff there to research. Thanks for the reference.
69hemibeep
Sponge Bob Square Wheels
there is one on each side see the hex head screw on the single wire
I found the problem while going around with a long ground wire to see if I could find the bad ground point. By chance while the car was running, I touched the core support body ground bolt which was too hot to leave my finger on for more than a second. The ground pad on the weld nut was clean which caused my attention to go elsewhere, but when I poked around it, the paint cracked where the nut met the core support. The nut/ground pad was not making good contact to the core support. I do not have a welder so I replaced the bolt with a longer one that protruded the core support by 1/2". Cleaned the paint from a spot on the front of the support for a ground contact point, put a flat washer and nut on then pulled the ground nut/pad back flat with the support. Cool as a cucumber and the brights are bright. The bolt was pretty darn warm on just battery but would get extremely hot when running. I would like to thank everyone who helped focus me on the grounding issue instead of the dimmer switch. I appreciate the help.
mac
What ?
great!!!!
69hemibeep
Sponge Bob Square Wheels
arty: