Question C3 Low beam headlights.

[Johnny 5]

I have a 77 Corvette. One of my low beam headlights will not work until I switch to high beam. Then all 4 lights will operate.

 

[Rocket Rob]

Four headlamp systems use 2 different sealed beam lamps. The outer ones are hi/low…the inner ones are high only. When you switch to high beam they all come on. The hi/lows use two separate filaments to accomplish this task. Buy a new hi/low sealed beam lamp…the low beam part is burned out (most likely cause). If that doesn’t fix it, it’s a wiring or connector problem ( unlikely cause). The old part numbers for these units were 4001 and 4002, can’t remember which is which, but any decent parts place should be able to help. Back in the day, ALL CARS used this system for 4 headlamp systems, so should not be too hard to find.

 

[Johnny 5]

Thank you. I’ll give that a try. I didn’t realize that there was a double filament in those old beams.

 

[Afterimage]

Rock auto is your friend.