Has anyone successfully wired a light bar on a 2021 F150 to come on with the high beams automatically? How did you do it??

 

should be pretty easy to do with a relay, I googled for a pic of the basic wiring for the relay and found an article that described exactly what you want to do, only you would need the 12v feed from the high beams instead of the low beams



Here's the article:

https://www.12voltplanet.co.uk/relay-guide.html

Scroll about 75% down and look for "1. Adding driving lights that come on with the headlight main beam" or search for it using CTRL+F

 

and use something like this so you aren't tapping off your OE wiring harness. figure out which wire is the high beam and tap off of the adapter.

21+ headlight adapter

 

Oh wow, I was actually looking for exactly this just a while back, didn't know they made these, that's awesome.

This won't work in OP's situation though, that harness is for the park lights, he would need a similar harness for the actual headlight plug so he can tap off the high beam signal wire. There are not many situations where you would need to do that though so I doubt there is a harness like this out there.

 

will work perfectly for the cost. Just use a posi tap off the high beam jumper wire. Or he could have our very own boostedgrey make him a custom one. One of them will be a very beautiful custom piece. One is cheap and just needs a posi tap. Who knows, he may want to add raptor lights in the future and is already set.

 

You're right, my bad, I thought this was a sub harness for the turn signals, I'm now seeing that its the main headlight connector. This would indeed function perfectly for what he wants to do. A custom harness would def not be worth the money for this simple project

 

I tapped my FORD grille LED spots into the driver side high beam wires, no issues. If I were doing so with a larger light bar, I would tap the same wires to a relay like Moogle posted above.

 

See, I did exactly this but when I switch on my highbeams the relay click's like an angry bees nest. Only when the truck is running though, when it's off the highbeam switch the relay and everything is fine.

 

I'm trying this same thing for the 2 led lights on my front bar, but when I do the lights run for a few seconds then go out. I can turn off the high beams then back on and get the same thing. Difference is, the relay/ harness I bought didn't have a separate power wire to trigger the relay. It just has one power wire that goes to the power source so I think it's drawing to much power from the high beam circuit but it's not tripping the fuse.

 

have the blue (trigger wire) of the switch harness tapped to the high beam wire of the starkey harness I posted above. Also have the rough country wireless switch so I didn't have to run any wires through the firewall, tied the RC unit to the homelink buttons. So hit hi beams, DD driving lights come on. Don't want them on for some reason, hit the remote or homelink off button and off they go. RC remote also has a strobe function to encourage idiots to get out of the left lane.

Works perfectly as far as I can tell. Just ran Forscan to check for any trouble codes and there were none.