I need some help on this one! I am converting my 03 250 over to a 7 pin plastic plug on the back of my truck. It had a 6 pin metal round plug on it when I bought it, and someone cut into my harness. So who has the wiring diagram for the back of my truck? There is 8 wires back there, and I only need 7. Any help is apreciated!

 

Can't you just unplug the trailer part and buy a new socket with the connector on it and plug it in and go. Way up underneath you just unplug the whole mess going to the trailer. Thats the way its designed.

 

Nope, Somebody cut mine factory plug off.

 

Here are the colors and pins for a 7 pin connector. What the 8th wire does is unknown in this case. The wire colors should match but if not the 6 pin horse trailer wires are listed after the 7 pole. You should be able with this to figure out what function is what. You can get a 12v tester for about $2.00 if you do not have a meter to measure which one is on when you turn on the different functions. I would hope that the wires in the truck match the standard colors so it should be easy to change connectors.

7 pole RV plug/socket.
# 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

6 Pin Connector
Terminal Marking Wire Color Function
GD White Ground
TM Brown Running Lights
LT Yellow Left turn/brake light
RT Green Right turn/brake light
ST Blue Brake Control
Aux Black Power

 

I still can not figure it out. This is what my truck has:

Orange-?
2 blue- electric brakes?
Yellow- Left turn
Green- Right turn
Brown- Tail
Black-?
White- Ground?

My plug has this:
White-Ground
Yellow-Left Turn
Green-Right Turn
Brown-Tail
Purple-Reverse
Blue-Elec. Brakes
Black-Auxilliary Power
Now how do I hook this up?

 

Buy a 12v cheep test light and do one wire at a time.... It aint rocket sicence.

 

This site below has photos that Bruce1026 was talking about.

http://firefyter_emt.tripod.com/elec.htm

 

I got it all figured out! I tried the testlight, but I could not get any signals or brakelights. Turns out that ford put a trailer fuse in the truck, and I blew it out somehow. I was scratching my head for 2 hours over a blowen fuse!

 

All the trailer circuts have there own fuse under the hood if I'm not mistaken.

 

They have one in the fuse block too. One of the best features in my opinion. Especially if you tow trailers that aren't exactly new... chaffed wires will pop a fuse every time. It's nice to know that you'll still have truck lights if you do that though.

 

ekeller, if you want that back to stock appearance you can trace the wire for your trailer harness back (i think almost to the left tail light) and you will find a connector there. You should be able buy the factory 7 pin with the flat 4 pin on the bracket from Ford. This is a better, sealed unit than the aftermarket 7 pin plugs. We need everything sealed up here in Michigan all that d**n salt they use is hard on trailer wiring.

Toyman