jferg92

The previous owner did a number on the trailer which I found underneath 20ft of electrical tape. Salt has taken its course and several connections are broken. How do I know which goes where and what connections on my 7 way rv plug do what? I'm inexperienced with electrical




It would make it so much easier if the wire colors were correct

RLXXI

That is a nightmare for someone that IS experienced, take it to someone with knowledge and patience.

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jferg92

There's also 11 wires coming from the front of the truck. theres two green two white a yellow and black going into the plug.......what a joke

Watt-maker

Thick guage white is the ground. It won't go all the way to the front. It should go to a grounding bolt on the rear section of frame. Brown w/white stripe is the tail markers. Green is right turn signal. Yellow is left turn signal. Thick guage blue is electric brakes. Thick guage red or orange is the 12v charge wire. The other wires probably go to the tail lights themselves. I can't remmember the colors for those. Get a test light or DMM to check.

EDIT: Almost forgot, light green is the reverse wire.

brulaz

If you have a 12V trouble light or Voltmeter, you could probably figure out which wire is which by trial and error.

Find a good chassis ground, turn on the left turn signal, and connect each wire through the 12V trouble light to chassis ground. The wire causing the light to blink is your left turn wire. And so on.

For some, like the backup lights, they may or may not be connected further up. Does the truck have a brake controller? If so you might be able to trace its wire back directly.

There will also be relays and fuses somewhere controlling these, especially #4, the 12V Battery Power. Make sure those are working.

jferg92

Thanks guys. I used a volt meter and found one of the broken wires was the power wire (got a solid 11.9). But explain this- when I connected it (the broken power wire from the truck) to each of the three broken wires on the plug, it still didnt power up the correct terminal for what the diagram says. I know the plug isn't wired incorrectly because I have used it before on multiple trailers and it has always worked. This doesn't make sense to me?

brulaz

Not sure if I'm reading you right, but do *not* take a "live" 12V wire and attach it any other wire going back into the truck.

EDIT: OK, probably you didn't do that.

If the bargman plug wires are disconnected, that's ok then, you should be able to attach the Live wire to any one of them and see what terminal in the plug is powered. You could also use the ohmeter function of the VOM to do the same thing.

Remember you will need a good ground to measure the 12V against.

EDIT: So maybe the plug is just bonkers. Or at least those terminals are. Maybe that's why those wires are disconnected. Somebody tried to figure it out but gave up. Do you have a good Bargman connector you can compare it to?

jferg92

Yes I do have have a good plug. It did work properly in the past so it was wired up correctly at one point. I just bought a new 7way and two feet of cable. I am going to hack it off the the axle and try to start fresh

Nateharsh

Subscribed.

dallas150

Are we on the truck side or the 7 pin on the trailer it self? What year is your truck? If 04+ ( unsure of previous years, may be the same) and were talking the wiring on your truck, you may want to just replace that harness. If it is 04 or newer there is a break away harness behind the bumper , above the spare tire drivers side. This harness takes care of park assist as well as trailer wiring. I believe it's around 100$ or less. Save your self the headaches.