Wiring the 7 pole RV Tow Vehicle Socket
View looking into the front (contact) end of tow vehicle socket.
View looking into the front (contact) end of tow vehicle socket.
There are two wiring codes for different 7 pole plug sets.
Most RV's use the RV wiring code for the type of plug/socket
that has 6 flat contacts surrounding the center round pin.
Semi's and other commercial trailers use the ASME
(American Society of Mechanical Engineers) type of 7-pole plug set.
This plug has 6 round contacts surrounding the center pin.
The wiring color code for this plug is not the same as the
RV 7 pole plug described below, and will be included at a future time.
| Terminal | Wire Color | Function | Location - Truck socket | Location Trailer plug |
| 1 | White | Ground | 7:00 o'clock | 5:00 o'clock |
| 2 | Blue | Brakes | 5:00 o'clock | 7:00 o'clock |
| 3 | Green | Running | 10:00 o'clock | 2:00 o'clock |
| 4 | Black | Power | 2:00 o'clock | 10:00 o'clock |
| 5 | Red | LT & Stop | 9:00 o'clock | 3:00 o'clock |
| 6 | Brown | RT & Stop | 3:00 o'clock | 9:00 o'clock |
| 7 | Yellow | Aux or BU | Center | Center |