7 Pin Trailer Plug

cjoffutt · Jul 22, 2020

Does anyone know which pin is ground and 12v? Trying to wire up a trailer connector to use my 3 point sprayer via the 7 Pin, but none appear to be supplying power. I'm assuming the large pin at 12 o'clock is ground?

Either that or I'm missing a fuse that will let the 7 Pin work. The pig tail on the tractor side goes to some other wire harness right between the rear tires, then to the rops lights and goes under the seat area.

Industrial Toys · Jul 22, 2020

Do they even supply AUX 12 volts to the connector on your tractor? Information for 7 pin is all over the internet. Ground in center, but if you didn't find the live (maybe with key on) ,maybe it's not there.

cjoffutt · Jul 22, 2020

Who knows if they did... I assumed they did since it appears to be wired in best I can tell.

But after testing earlier with key on, and then tractor running I doubt it. There isn't a fuse labeled for trailer plug, closest thing is 'user power' but it doesn't even have the metal clip for the fuse to lock into.

Was mainly just wanting to make sure I wasn't missing something simple before I ran wires from the battery back to it myself.

Industrial Toys · Jul 22, 2020

That would be a shame if they didn't. But hey, it's another three dollars worth of copper.

RickB · Jul 22, 2020

Tractor operator manual?

Diggin It · Jul 22, 2020

Here is a generic diagram. Unknown if it's what you need:

Industrial Toys · Jul 22, 2020

Boy, I got that wrong. I thought the center was ground! Maybe thinking the Flat RV plug.

cjoffutt · Jul 22, 2020

Industrial Toys said:
Do they even supply AUX 12 volts to the connector on your tractor? Information for 7 pin is all over the internet. Ground in center, but if you didn't find the live (maybe with key on) ,maybe it's not there.

Come to find out, 12v isn't supplied to the plug on the tractor side at all. Rather lame in my opinion.

Guess I'll find an unused fuse slot in the block next to seat or use one of the 'add a fuse' things. Not a real easy clean way to run wires from the battery all the way to the back.

denchen · Jul 23, 2020

There is two types of 7 pin trailer plugs. they look the same but the pins are different. For running lights, brake, indicators a 7 pin `N` type is used. For auxiliary a 7 pin `S` type is used. The wiring for this is as you look at the `plug`, at pin 4, 6 o clock, is a 12v supply. Number 3 pin, at 7.30, is the common return.

Dwellonroof · Jul 23, 2020

MichiganIron · Jul 23, 2020

Dwellonroof said:
View attachment 664108

Make sure you turn on the Headlights with the Key Switch on. There isn't any power to the plug until you use one of the plug functions (lights, turn signals, brakes, etc.)

Hope this helps,

John Skull · Jul 23, 2020

eTrailer.com is a good site for parts and the following wiring diagrams:

Attention Required! | Cloudflare

Industrial Toys · Jul 23, 2020

Funny, I just unsubscribed to E-Trailer. Bought one dammm thing from them (over the phone) and they have been E-Mailing me daily since !!!!!!!!!!!! Terrible business practices!

denchen · Jul 25, 2020

Looking at the posts on here, it seems we do things a bit different to you guys on this side of the pond. For normal `autos` we use the two seven pin plugs or the latest one thirteen pin plug. Heavy `trucks` have a different size plugs.

IXLR8 · Jul 25, 2020

I think I have found references to at least 4 different ways to wire up a 7 pin plug. None of the ones shown in this thread match what I have on my truck!!??

bcp · Jul 25, 2020

It can get confusing with diagrams showing the front or the back of the socket, and the front or the back of the plug.

And in some that appear different, the pin function is the same, but the color coding is different.

Bruce

cjoffutt · Jul 25, 2020

Long story short, per the manual there isn't a 12v supply to any of the pins.

To remedy this issue, I just added a 10 amp fuse to the block next to the seat, ran a wire to the tractor side plug and a ground as well. I wasn't concerned about messing up the random pinout it already had as I'll never pull a trailer down the road with the tractor, that's what the truck is for. But if I ever need to, all I have to do is remove the 12v supply and put the original wire back in.

Sprayed about 50 gallons of roundup this morning with no issues at all.

CoyPatton · Jul 30, 2020

Industrial Toys said:
Do they even supply AUX 12 volts to the connector on your tractor? Information for 7 pin is all over the internet. Ground in center, but if you didn't find the live (maybe with key on) ,maybe it's not there.

Here lies one if the big problems with answering your question. There is no universal standard for a 7 pin connector. There are at least 2 standards for these plugs.