How to Determine the Functions of the Pins on a Vehicle Side 7-Way Trailer Connector

Question:

Will this identify which wire is which function including 12v + and -?

asked by: Mike N

Helpful Expert Reply:

The Pollak circuit tester # PK12741 will tell you which functions are working in a 7-Way trailer connector but it doesn't tell you the location of the functions within the connector. But I can tell you that.

If you are looking at the face of a vehicle side 7-Way where you would connect the trailer:

1 o'clock position is 12 volt power
3 o'clock is right turn and brake lights
5 o'clock is output to trailer brakes
7 o'clock is ground
9 o'clock is left turn and brake lights
11 o'clock is running lights
Center is Auxiliary power or reverse lights

I have also included a picture and a link to our help article on wiring. Ignore the colors listed and focus on the functions and the positions they are in.