License plate lights

Hey smart people. Part of finishing up the bumper install is to wire in new license plate lights. I have yanked the harness for the blind spot and parking sensors so I need to find new power for the plate lights. Two thoughts. Splice into trailer harness or tail lights. Not sure which is easier or makes the most sense. Obviously, I need the plate lights to turn on when I turn on parking lights. Does anyone know which wire I need?

 

Found this in my Haynes manual.



If I’m reading it correctly, power (green) out of the plate light should connect to green on the tail light. Doesn’t seem to be working. Turn the light on and I get tails but no plate lights.

 

Where are our wiring geniuses? @TundraTex ??? @eledobleu ???

 

Why don’t you tap off the stock license plate lights?

 

wiring harness is no longer there. i pulled it all out when i yanked the bumper off yesterday. i have another idea but it's a bit more invasive than i'd like. it'll also render the harness useless should i ever need it in the future. not sure if it's an issue as the blind spot and parking sensors probably aren't going back on the truck.

 

On the trailer harness, I believe brown is the park lamp wire. Test with a meter to confirm though.

 

I’ll try that tomorrow. Thanks.

 

just got this working. the wiring diagram i posted above is correct. i must have been having a, um, moment the other day. with the new lights that came from expedition one, i had assumed that black was ground and white was power. silly me. white is the ground and black is the power. that's not just me, right?

anyway, black from the new LED plate light, goes to green in the tail light. white goes to the white/black in the tail light. plate lights are now on when the truck lights come on.

next step, wire up the BD squadrons for the reverse lights. it's a long way from the end of the truck into the engine bay...