I have a 2010 ranger and am trying to install a Peak back-up sensor. It says to connect into power, connect to the two wires going into one of the back-up lights. But how do you determine which wire is positive and which is negative. They both look to be the same color.

Any help is appreciated.

 

Put the truck in reverse with the key in the run position or start the truck.
Using a probe test the wires.
Mark the wires.

Another thought:
Most of the time Ford grounded there rear lighting to the frame at the back, start to trace the wires and see where they go.
If the first wire starts to go toward the front of the truck chances are it is the switched power wire, trace the other and see if it is connected to the frame.

 

Thanks, I got it figured out. Now I just have to wait while the company replaces one of he bad sensors.

Thanks again.