First post here. Just got a 91 f250 XL 4x4 2 tanks and I can't for the life of me find the plugs I'm supposed to pull apart to put my 4 flat harness in between. Should be right by the hitch under the bumper if I'm not mistaken? I have the tow package, class 3 hitch, trans cooler all factory. But no trailer wiring for some reason and I can't find the plugs. It's an automatic if that matters but I don't believe it does.

 

If you have one of those aftermarket tee plugs, then you need to unplug the factory plugs that go to the factory lights in the bed.

If you are looking for a factory tow package plug, I don't think you will find one. They changed it from year to year, but I believe you will find your factory tow wires are blunt cut wires, and will be wrapped with tape inside the original harness. If you want to find the factory tow wires, you will have to unwrap the harness and you will be presented with wires that are just cut off.

Orange will be the trailer charge wire

Brown/white will be the marker lights.

Yellow will be the left turn/stop

Darkgreen will be the right turn/stop

 

I do have one of the T's and the plugs for it are what I'm having trouble finding. Sorry for not making that more clear

 

There should be plugs over on the driver's side back corner of the bed/frame area. These are the plugs that you would take loose if you wanted to separate the wiring coming from up front along the frame, from the wiring going to the rear lights in the bed, so you could lift the bed off. If you do not have any plugs there, someone has cut them out.