Blinker and Brake Light issues! PLEASE HELP!

[NateCharger]

Blinkers and brake lights work great, until......I turn on the headlights, then they barely work at all!!! Very dim...
Any ideas??? Car is a 71' Charger R/T

[A383Wing]

little more info would be nice here...is engine running or not? Are all the grounds from engine to firewall still there?

[NateCharger]

Thanks for chiming in! The car runs great. Where exactly does the engine ground to the firewall?

[A383Wing]

not sure if yours has one or not, but on 66 & 67 cars, there is a ground strap from rear of engine or intake to the firewall for ground....if all you have is a battery cable to engine block, you need another ground from either battery to rad support or engine to firewall...good clean connections are a must

[NateCharger]

I have a ground from the battery to the engine, and from the battery to the radiator support. They are both clean as well.

[A383Wing]

sounds like a ground issue for the headlights or the parking lights up front...