Wiring the 7 pole RV plug.
There are two wiring codes for different 7 pole plug sets.
Most RV's use the RV wiring code for the type of plug
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.
This plug has 6 round contacts surrounding the center pin.
Pin locations for the standard RV 7-pole plug.The terminals are numbered inside either the
or tow vehicle plug (truck circuit number one should connect
to trailer circuit number one, etc.), and certain wire colors
are used for the different circuits. The wire colors on the
truck end may be different, but the trailer should correspond
to this color code. The positions indicate where on a clock face
the terminals are located - when you are looking into the plug end.
||Location - Truck
||LT & Stop
||RT & Stop
||Aux or BU
See also RV Wiring