56 F100. I couldn't tell during the daylight and returned the battery to the donor truck before dark. When the high beam lights are on, is that in addition to the low beams or instead of the low beams. Using my power probe to power each wire independently it looked like they may be independent of each other. I don't know if the bright/dim switch on the floor combines the two. My floor switch is intermittent at best. Bye the way, the power probe is a great tool for people who are not adept with a digital multi meter. Best $100.00 I have spent......twice.

 

AFAIK all '50's Fords are "either or", low beams or high beams, the floor switch directs power to one of the two, never both. NAPA sells floor switches cheap:
NAPA AUTO PARTS_Headlight Dimmer Switch

 

I agree either on or off... Some headlight switches will activate both at same time only while the switch is depressed .. Once you let off it will change states to either hi or low....

 

Thanks guys that's what I thought. I needed to know that before I could proceed with all of my headlight, parking light, taillight wiring. Now I'm on my way. The people on this site are the bomb. Matt

 

The sealed beam headlight would get really hot if both elements were on simultaneously.