This is what I bought on amazon. Now Tom Bronco parts has a better looking harness but it was 50 shipped vs 17 so I took a chance.
This one has two relays, it's own fuse and good size terminals and 12 or 16 ga wire. I am not sure it's a decent size.

The headlights are surprisingly good quality being glass, metal and sealed with some type of epoxy based on my inspection from one of the vent caps Also I wasn't about to spend 500 dollars on some JW speaker lights when these came out great. The harness would have been perfect if it was about a foot longer on the relay side just for cleaner mounting purposes.
I would recommend using a drill with extensions, a magnet for runaway screws and some self tapping #12 3/4 screws for ground and relay anchoring.

Headlights come out easy once you undo the retaining ring which is 3 screws on each side.
If you are like me and get clumsy and drop a screw. They are 4 mm .70 fine thread pitch. I had to buy 2
Make sure you grab both the plug and wire together to disconnect and reconnect the original plugs.(keep in mind these vehicles are over 40 years old wiring maybe intact but the plugs could be brittle.)


There are several holes that you can choose to run the wires through the core support.

Now the harness only has one plug needed to activate from the dash and foot switch so the drivers side one should be masked over with electrical tape to prevent shorting out the circuit. You could use dialectic grease for good measure too.
Also each plug has a separate ground wire so I tried my best to mount them low enough to get through the grill and the core supports and not be too visible. Self tapping screws are your friend.

The passenger side you wire the red to the positive battery terminal. Find someplace close to mount the relays

Plug the black plug into the factory connection on the passenger side and the ceramic plug into the LED light and put back the retaining ring and test.

 

Nice write up. Does your harness have the option to (when high beams are on) have BOTH high and low lights come on?

$50? $29.95 https://www.tomsbroncoparts.com/prod...ord-bronco-new

NOTE: Our headlight harness includes a pre-installed diode that allows the high and low beams to emit light at the same time when the brights are turned on. Should you need to disable this feature, simply remove the diode from the wiring harness.

 

Its 50 with shipping. 29.99 plus shipping. Cheapest shipping for me in GA was 22 dollars and took a week. I got mine in two days.
If you have other parts you need I would say go for the Tom bronco harness. The LMC harness the same price but it's got yellow cable wrap and I don't think it has a fuse.

Now I checked with the high beams on all lights are on. So both low and High come on. Both foot and dash switches work to cut on and off.

 

Actually you can see it in second to last picture.

 

nice. I have the same harness and head lights for my 71, but i'm a little way off from installing them. glad they seem to work good.

 

Do the headlights say dot on them? I have seen aftermarket headlights that blind oncoming traffic because they do not have a height cutoff and are not dot approved.

Nice truck!

 

Thanks, yes they do say DOT on them. There are several that say for off road use only in the description. This is one of the few that Specifed DOT. If you want absolute certainty grote makes a good light for 300 vs 5-600 a pair.