Fuel pump and level sensor are on this connector as well. BTW you probably have to drop the tank to switch out the harness.

 

Or lift the bed. Good time to look at that rear brake line as well.

 

Dropping the tank is the only way to get it behind the tank. Doing both is the best option

 

I have two connectors down there by the front left tire. One big bundle of wires comes from the firewall, goes down to the wheel and splits into two groups of wires with those connectors, then goes back into one group of wires and runs all the way to the spare tire.

Lucky for me I was getting ready to swap my 26 gallon tank for a 36 gallon tank, so I guess that makes now the time.

 

I'm not of town until Monday but I could you get you pics then if you don't have one but then.

 

FYI, I have a backup factory 7 way trailer harness and connector. I took a couple of photos of it so you can see the wiring and their colors. The wires are split into two connectors - one 3 wire and the other 4 wire.

 

That is quite interesting. Those connectors plug in at the rear of the truck? I don't have any type of connector at the back of my truck aside for each taillight. To get something like that I would probably have to splice it all in.

I'm gonna try to find the connector that plugs in near the front and has the blue, purple, and red/orange cables I need and pull them about halfway down into the frame in that factory conduit and then run them back all the way. I'd prefer cables to any kind of splicing because I don't trust my skills in that area too much and the underside of the truck sees a lot of water.

edit: looking more closely at those wire colors, it looks like the small connector is for the reverse/turn signal/running lights, but I would have thought there were four wires for that, and I also didn't know those wires would get put on a different harness.

The thick connector definitely looks like it's got all the wires for a brake controller. Black probably for neutral, Orange/red for 12v, blue for brakes and orange/brown for reverse.

 

My '96 Ram 2500 4x4 truck came with the factory towing package, complete with the 7 way connector mounted on the trailer hitch. The two plugs on the back of the connector plug into the wiring harness on the left side of the frame just ahead of the bumper.

 

For those of us without the factory wiring that just wish to tap into the existing harness.On a 2001 2500 gas. in the rear tail lights there are 3 wires feeding the high bulb that does brake , running and turn signal lights.
I think is says ground, which is black, there is a green wire and a green with a stripe on the other side that is running lights and a third wire top wire I can't remember. I believe they are labeled low and hi power.

What do I tap into for running lights, brake light, and turn signal. Is there a schematic. Sometimes things that come to you for free are very expensive.

 

Got my good spectacles out. you will find these colors before the plug into the factory taillight sub harness.
A BK/YL wire is for your trailer running lights. Brown.

on the left side DG/RD will tie into red stop, turn

on the right side a BR/RD will tie into green stop turn

Find a nice spot and ground your white to the chassis.

you might think that yellow should go with yellow, brown with brown, and green with green, but that would be too darn simple.

Pg 979 of the FSM. double check the work, I am old.