I just soldered in H3 headlight connectors to replace my 9007 bulb connectors, upgrading the front end of my Ex from the faded, yellow 2000 headlights to 2005-2007 XL Sealed Beam headlights. (Gonna sell my 2005-2007 Clear headlights, as I prefer the sealed beams.)

Man, I thought I'd find 14 gauge wire... The high beam wiring looked decently thick, at like 16 Gauge.

For the low beam and grounds, though... I think I've seen thicker wire in cell phone chargers, and those are rated at 2 amps.

You figure a 9007/HB5 bulb is rated at 55/65 watts for Low and High beam respectively. At 12 volts, that's 4.6 Amps low beam and 5.4 Amps high beam.

Welp... Time to start looking at building a wiring harness.

 

16awg is good for about 11 foot run drawing 6 amps.

https://www.wirebarn.com/Wire-Calculator-_ep_41.html

 

I used this for my headlights: 9007/9008/H13 Conversion Harness Pigtail Set



Stewart

 

I upgraded the entire headlight wiring on my Expedition with a relay kit from Daniel Stern:
Daniel Stern Lighting Consultancy and Supply

Doing this kit gives your headlights power straight from the battery (via a relay) and not through the headlight switch. It made my lights noticeably brighter.

 

My Excursion used to be a State of Oregon Public Works vehicle. When I got it, I removed parts of an emergency lighting harness, but I kept it around somewhere...

There's a Code 3 model 710 WigWag that has a set of relays for the headlights and gets battery power straight from the battery.

I'm gonna put that back together... Minus the emergency lighting part, obviously.