Hey guys n gals. I was just curious if the wiring that goes to a trailer, on the back of a semi truck, is the same as it is on the back of a pickup truck. Reason I ask is I have a pintle hitch trailer that i have wired for behind my pick up truck, and I was going to pull it behind my dump truck. It has a 7 flat prong plug on the trailer, and the dump truck has the regular trailer plug on the back (not sure of the correct term, but requires a little different of a plug). I was going to make an adapter for it (or buy one if they are available) but just wondering if the wiring is generally the same from a pickup truck, to a "semi" truck.
The colors and terminal locations are not the same. The 7 terminal "RV" plug came in much later but they just couldn't use the colors standard for ever in trucks, they had to change. That kind of stupid stuff just grinds me. Sorry for the rant. I've never been able to find an adapter. If there is one I'd sure like to know.
I have purchased several different adapter plugs from NAPA for trailers. They may have a plug that will work but not necessarily have the same wire functions from one truck to another. As posted their is no real standard from one brand to another.
I've bought adapters from the RV to six and five pole round but I've never found one that goes to the semi truck 7 pole. Just to add a little interest if you buy an adapter there are two versions of the seven wire RV plug. Some of the adapters have a jumper wire inside that you can change.
Thanks guys! I was going to test the prongs anyways just to be sure, but it was raining today so i thought I would post it on here. There shouldnt be much for getting it to work though, and if i cant find an adapter i will try and make one. Making an adapter shouldnt be tough, and it might be easier then swapping the plug around each time i wanna use the pickup truck instead of the dump. Thats also good info to now for when a guy goes to swap trailers too. Each guy I have worked for must have had all the trucks/trailers wired alike, cause ive never had a problem with lights and whatnot working, but I just never thought about it much either! On Edit: Or do you guys think that I should just install a rv plug on my dumptruck, that shouldnt be tough to do, throw some wires from the dump plug to that one, run one single wire for the electric brakes, the power and ground, signals and brakes would all be at the dump plug...
thye make a 7 wire to 6 wire plug adapter but i think that it is rather pricey but it works if trler is wired per code or the truck also Good luck
I use a trailer wiring box like this on my equipment. On trailer and trucks. Locate one at rear of truck. Then you have easy access to all the rear wiring and can run whatever type connector you need out of it. or several types.
I made an adapter to convert 7 round to 7 Rv. It was pricey for the ends, we have since changed our dump trucks to the 7 RV receptacle. I would recommend changing it over.
My local WalMart carries 6 and 7 plug adapters. Or at least they used to. That is where I got mine. There are two universal wiring formats. The difference is in the constant 12V supply and the brake 12V supply. If your truck is wired one way and the trailer the other, you will have brakes all the time. Swapping these 2 wires solves the problem. Some of the older vehicles don't have a constant 12V supply to the trailer. In this case, you won't have trailer brakes if wired wrong, and will have trailer brakes if wired right. The ground and lights are the same in both formats.
I think that the 7 RV plug has the brake and turn signals combined where the 7 HD has separate brake and turn signals. I had to wire in an adapter when I changed the truck over to 7RV. It came from a boat trailer store. There's a place in PA that carrys plug in adapters for 7RV/7HD (both directions) Weaver Distributing (1-800-weaverd) no web site though.