trailer light wiring color codes

[fordnut85]

4 wire
Brown--Tail lights
Green--Right turn
Yellow--Left turn
White--Ground


6 pin round, same as above along with....
Blue--Electric brakes
Black or Red--12v positive
If you are looking at the back side of the truck end of the plug, starting at the top and going clockwise they will positioned-brn-blu-grn-yel-wht-with the center bieng black or red.


7 blade "RV" style, same as above along with
Large yellow or purple--12v positive
If you look at the back side of the truck end of the plug, starting at the top and going clockwise they will be positioned--brn-yel-wht-blu-grn-blk or red-with the center bieng yellow or purple


The 12v positive leads are ususally used to charge trailer battery or operate backup lights. It can also be tapped into the backup light circuit on the tow vehicle to disengage surge brakes while backing up.

Most trailer lights use this color code
Wht--Ground
Black--positive for light function (i.e. tail or marker lights)
Red--positive for signal function (i.e. brake lights or turn signals)


Hope this helps someone