89 F 150. At the headlite, there's a green w / black stripe and a red w / black stripe. Which one is low beam ?

 

Low Beam is green
High beam is red

 

Midnite 1987 I found that the red wire is low beam and the green wire is hi beam. I was just lookin for a shortcut and didn't want to get out the voltmeter, is why i asked.

 

I read what infound in here. Guess that's backwards lol
https://www.ford-trucks.com/article/...r_Brights.html

 

Well i wouldn't trust that article. That person is talkin usin #18 gauge wire and doing a headlite wire upgrade. I would never use the same gauge as what was stock. Nothing smaller than #14 for me.

 

The 18 ga wire is used to turn the relays on only, the current that travels to the headlight is all 14 ga.

 

Or it can be 12 G.too. Although i feel that 14 G. is plenty enough for most applications that run bulbs of less than 120 W. for both filaments glowing when brites are on. Amp draw would then be about 8 A. going thru 14 G. wire that is rather short since the upgrade would be close to the power source and the wires to headlites are not very long either. 8A. in to relay and 8A. out to headlites.