Is there such an adapter?

[dwcopple]

Black is GND then?

 

[HotWheelsBurban]

Black is GND then?

No, the ground wire is white, and should have a ring terminal to attach it to the frame. If the spare is out of the way on a pickup, there's lots of room to get to crossmembers. I used the thinner one ahead of the bumper, makes it simpler to drill the hole for the screw.
It's fully connected, loomed up, and I can tuck it up out of the way, so it doesn't drag or catch on anything. Towed twice, and the lights worked properly on both trips.

 

[dwcopple]

No, the ground wire is white, and should have a ring terminal to attach it to the frame. If the spare is out of the way on a pickup, there's lots of room to get to crossmembers. I used the thinner one ahead of the bumper, makes it simpler to drill the hole for the screw.
It's fully connected, loomed up, and I can tuck it up out of the way, so it doesn't drag or catch on anything. Towed twice, and the lights worked properly on both trips.

So what is the black wire for on the oem plugs? There is no white on either

 

[dwcopple]

Nobody knows huh? Sweet.

 

[PlayingWithTBI]

So what is the black wire for on the oem plugs?

I'll guess, the black wire is 12Volts for interior lights in a trailer or something like that. Check it out with a voltmeter.

 

[someotherguy]

Nobody knows huh? Sweet.

Before you start throwing jabs you may want to invest in a test light and the free-to-download service manuals here on the site. Wiring diagrams are included. You've got a lot of good advice on here already but nobody's gonna come do the work for you unless you open up that wallet.

Richard

 

[Caman96]

Absolutely, I asked a similar question a year ago and it was you @someotherguy that gave a similar answer. I still went out and verified with a test light. Respectfully

 

[dwcopple]

I'll guess, the black wire is 12Volts for interior lights in a trailer or something like that. Check it out with a voltmeter.

What? On the factory tail lamp plug? I think some of you are getting confused here

 

[Caman96]

What? On the factory tail lamp plug? I think some of you are getting confused here

What do you mean by tail lamp plug?

 

[dwcopple]

What do you mean by tail lamp plug?

The plug that snaps into each tail lamp housing. I posted pics of them