Ok I just cant't find it here. Next week I'm gonna rewire my trailer. Its a triple axle cargo with brakes on all 3. I found some trailer wire with 4-12 Ga/2-10 Ga/1-8 Ga. Would just be a goodwire? Also I need to relocated my connector on the truck into the bed for the gooseneck trailer. Can this wire be used there also, or is there a "kit" that interconnects into the truck harness? The truck had a connector in the bed. (has a hole there already) and a bunch of scotch locks on the harness going to the factory trailer connector. Also what is a basic wiring diagram for a trailer? I need a diagram on how to wire up a breakaway switch, and how the brqakes are connected. Would the 1-8 ga wire be a ground for everything on the trailer? I wanted to add a battery to the trailer also. Well back to surfing on line. Thanks -Bob

 

Go to a commercial trailer place and get some 7 wire color coded trailer harness, use arctic-flex if you live any where that see's minus temps more than 30 days per year. Also look for commercial terminal boxes to have at least 2 to have access to trouble shooting spots to connect into. They have color coded terminals inside, trailer color codes usually come with a 7 pin plug to match your recepticle on truck-follow the code and leave master in glove box. I will only use the double wall shrink tube on all connections to seal wire from moisture and corrosion. Break away switches are simple, Black battery wire goes to + terminal from truck, + terminal goes through to break away switch and then to the hot side of the brakes in front terminal box, - battery terminal wire goes back to - terminal in junction box. Electric brakes don't matter as long as 1 wire is hot lead from blue and the other is a true ground connecting back to ground in terminal box for a direct connection to truck ground. Do NOT use any connector type device that can't seal out moisture- easy is not always easy on the side of the road or when pulled over by the cops for no lights. I usually place my 2nd juntion box on the frame near the brakes due to the number of connections, I try to run the back electrical from the back box and the front off of the trailer cord input box. I also spend the money for sealed plugs and coil cords like Bobtail Products as they don't drag and will stretch up to 12' when necessary. Hard wire in sealed beams with pig tails, cheap lights are a total frustration down or on the road but truck stops carry the bulb units just about anywhere. RV lights are at best junk but are cheap, I don't like $100 tickets for burn't out or screwed up $3.00 light units from bargain stores. PK

 

Cool, ok so can everything be grounded to the triler frame at their mounting location, then have the ground picked up at the hitch then fed through the connector to the truck ground? It would save a little wire, but like you said, don't weant to be on the side of the road for taking shortcuts.. Thanks -Bob

 

I stopped using the trailer frame for a ground and use the heavy white wire supplied in the 7 wire trailer cable directly back to the plug/terminal box. I use the ground through the plug and then to the truck frame much more effecient and easier to maintain continiuty. Electric brakes require the minimum resistance possible to work their best as a controller sends pulses from 1-12 volts depending on demand of the braking requirements. PK

 

So long as you ground through the connector, you should be OK. It's not a good idea to depend on the hitch for ground continuity between the truck and trailer. A hard wire ground through the connector is much preferred.

Rusty

 

I found the official color code guide #1-white-ground, #2- blue-electric brakes, #3-green- running lights, #4- black- battery charge circuit, #5- red- left stop/turn, #6- brown- right stop/turn, #7- yellow- auxiliary circuit. I don't have the truck circuit colors as they vary from year to year sometimes for whatever reason. The trailer harness wire I use has proper sized wire already in the cable. This color code will not match the code for commercial trucks in the junction boxes, just put eyes on the right color and forget what they tell you for purpose to match. Set up your truck like this and you will be able to pull 90% of the trailers out there without building patch cords. PK

 

You have a fun project ahead of you! I did the same to my horse trailer about a year ago. I grounded the trailer at the front and back and I connected brakes directly to the ground wire. I ordered nearly all of my stuff through http://delcity.net. I bought 100' of wire for same price I could buy 40' locally.

I decided to solder and heat shrink all of my connections. It was definately a PITA, but it should be much better. You may consider soldering the wires into the connector as well.

After a good solid weekend of wiring, my trailer now lights up like a Christmas Tree!

 

I was looking at delcity also. They have a 7con wire with 4-12 Ga/2-10 Ga/1-8 Ga. I Think the 8ga would be the common grounds for the trailer, then back through the connector to ground at the truck. So I'll prolly get that 7con wire, run it to the junction box and then could I use a 2 conductor wire to run down each side of the trailer? I guess that is more of a preference, but I should really only need the 7 con to the JB right? Then it all splits up from there. I also need inside lights, and want to put a deep cycle battery in the trailer. Any problem with using the 12V feed form the connector to charge it. I would be powering anything, just mainly using it to charger the bat. Thanks. -Bob I got a pic of the trailer kinda in my gallery, gonna replace al the wire!

 

No problem at all - that's what the +12VDC terminal in the connector is there for - to keep the trailer batteries charged. All RVs are set up this way.

If you're doing this from scratch, you might want to consider installing a battery isolation relay on the truck side of the connector. This relay is energized off the ignition switch of the truck and disconnects the truck batteries from the trailer batteries when the engine is shut off. The stock Dodge trailer tow harness has the +12VDC terminal hot at all times - this can result in discharged truck batteries if you use a lot of 12VDC power in the trailer with the truck shut off. Alternately, unplug the 7-pin umbilical from the truck when you're going to be in the trailer using 12VDC power for the lights, furnace, etc.

Rusty

 

Thats really up to you. I ran my 6-way all the way to the back. I wanted a ground in the back, and it was cheaper instead of buying individual wires. Plus I like the the idea of being able to add accessories easily if needed. I did split some of the wires into a JB at my gooseneck for the clearence lights and left a wire for interior light if I want to add them later. It is a pain working with the 6-way wire through the length of the trailer though.