Two possibilities come to mind here. One is that the ground for the headlights is bad. Two, the wiring to the headlight socket is incorrect. With two of the headlight terminals interchanged, they will still light but not correctly.


1951 GMC 1 Ton Flatbed -- It is finally on the road and what a great time I have driving it!
1951 1 Ton Completed


My Chevy Master 4 Door is on the Road!