Wiring harness help

[Curtid]

Installing a 7-pin trailer harness on my 05 sports Trac there is two wires in the harness behind the license plate that's athey say positive andpositive and negative I'm just wondering if I can use the positive wire for the power supply in the seven wire plug

 

[njbronco]

i noticed them on my harness as well. but I have an 01. I was thinking they are probably for the reverse light and charging circuit don't think there would be a negative wire.

 

[Curtid]

Humm. I'm just looking for a 12 v. Wire .For the power supply on trailer plug. To keep the trailer battery charged just trying to figure out if this circuit will do the job

 

[koda2000]

How about the aux power port in the bed? All the other wires in the rear are for lights and would not have voltage unless the lights are on or you're stepping on the brake pedal.

 

[njbronco]

That it will not. It’s too thin gauge. You should run a ten or twelve gauge from the battery back for that with a fuse. Or use the power port. If it were mine I’d rather know the wire is safely gauged and fused.

 

[trey edr]

I use aux power port and its helpful