Wiring diagram

[Smitty57]

Tight turn pulled my 7 pin wiring out of the junction box, therefore I have no idea which wires are connected to the 7 pin wiring harness. Does anyone have a wiring diagram of the Voltage to connect to the 7 pin harness?

[sundancer 87]

https://www.google.com/search?q=7+pi...ITg5sSJTCVsygM


Pretty much the way it's done universally.

[Smitty57]

My wiring doesn't seem to match a specific color coding system. I have all the "colors" of wiring but even more such as white with brown stripe, two 12 gauge red and one 8 gauge red, etc. Also, how is the trailer disconnect switch wired? It has 2 black wires.

[sundancer 87]

Originally Posted by Smitty57

My wiring doesn't seem to match a specific color coding system. I have all the "colors" of wiring but even more such as white with brown stripe, two 12 gauge red and one 8 gauge red, etc. Also, how is the trailer disconnect switch wired? It has 2 black wires.

Yeah, the color code from the trailer is whatever the blind installers have that day. The pin location is to determine what pin does what. You'll have to jumper from those pins to the trailer to see what lights up.

I don't know what you are pulling so I can't help you with the disconnect switch. If you are talking about the break away switch then the colors aren't important as the switch opens a circuit when broken.

[wahoonc]

I have been tasked with rewiring several trailers at work...

The first problem is that no two are wired the same, the second problem is that the trucks are not wired the same either.

The best bet will be to figure out how your truck is wired. Then use a battery to energize the circuits on your trailer one at a time to figure out what is what, then wire your pigtail accordingly.

One thing I have learned is to use a junction box at the head of the trailer, that way when the pigtail gets damaged again, and it will, it is much easier to rewire. The other thing I do is take a picture of the correctly wired junction box, then laminate it and put it inside. Saves a lot of time.

As a general rule, the blue wire is brakes, the heavy red wire is power feed, white is almost always the ground. Other than that it is a crap shoot.

Aaron

[OldOneTwo]

Go to etrailer.com they have diagrams for the color coded wires. The breakaway switch closes a circuit that applies full battery power to the brakes or in Electric Hydraulic Disc systems applies full hydraulic pressure to all calipers.