Extra wire on pigtail harness.

[CC Hurl]

Hi folks, I have an extra wire on my pigtail harness that comes from the truck. It is green. The harness only has four so I am a little confused as all the lights seem to be working fine. Is this a ground wire of some sort? I was wondering if I was supposed to connect it to one of the other colors for some reason? I have not connected this wire to anything in the past but thought I would ask here to see if anyone could explain. Thanks for your time.

[Bigtom]

What colors do you have, Because green should be right blinkers. Do you have a blue wire or fadded blue? Is there constant power to it?

[gunmunky]

I used to have a trailer that had reverse lights. You can use a test light to see when that wire gets power.

[chris63]

A "typical"light harness should be as such:Red wire +fused battery,White wire-ground,Yellow wire left rear blinker/stop/brake,Green wire right rear blinker stop brake,Brown wire tail,side,license plate,Purple wire backup lights,Blue wire electric brake control circuit.Hope this helps.A multimeter or test lamp might be helpful.The multimeter can test voltage as well as current flow.Happy wiring!!!!!c63

[CC Hurl]

Thanks for the replies you guys. From what you guys have mentioned I am thinking it is backup lights or electric breaks. Just thought I would ask on here and I am glad I did. Lights are all working fine and now I know what the extra wire is. Thanks again for your time.