Yes I am aware if I pour over wiring diagrams I will eventually figure it out but those things are seriously convoluted and hard to follow sometimes. I am hoping someone can tell me what this plug goes too without that pain. Since I have owned my truck half the wires on this are cut or chewed up but everything has always seemed to work fine on the truck so not sure what it is and have not really worried about it. But it is obviously a stock plug and probably needs hooked back up if I knew what to order, otherwise I will have to cut one off a truck at the salvage if I run across one.

 

First hint is , what does not work on the engine or the rest of the truck?
Good luck.

 

Everything has worked on it as it should since I have owned it.

 

Appears you don't have to worry about it then if all is ok.
Hooking it up accomplishes nothing if everything work--no?
Good luck.

 

Yea I understand your logic and I do get your sarcasm but I am pretty sure Ford did not put it there for no reason and I am sure it goes to something whether I realize it is not working or not. Obviously it goes somewhere and does something--no??

 

I have no idea what it is for. It could be for some accessory or feature that is not on your truck. Sometimes Ford would build wiring harness with every possible circuit on it rather than make a half dozen different ones for variously configured trucks. That would explain why everything on your truck works fine. If you don't have something it can't go wrong.

 

It is hard to see in your picture but it does look like the plug is in fact plugged into its mate correctly. It looks like the connection serves as a jumper between two harnesses.

If you have wires that are cut, tell me the colors and I'll look it up.

 

I explored my service manual wiring diagram. The connector is C139. There are 12 wires. By hovering over each pin in the Connector Viewer it explains what each wire does. Many are sensor signals (MAF, IAT, oil pressure, AC clutch relay output, ground, power). My guess is that someone was digging at the wires trying to diagnose a problem. If there are any cut wires, tell me the color or pin number

 

Yes, that is a jumper connection that connects two sections of wiring harness together. This is apparently not a picture of your engine compartment? I am only saying this because it appears to be hooked up and fine in this picture.
If this is infact not your truck, and you have one side of the connection dangling, I would dig around in the piles of wires you have there and see if you can find the other side. there will only be one that will fit it, if it is indeed there. It can't go far either, because they are only as long as they need to be, in order to hook them up. Curious, is this truck a manual transmission? If so, perhaps that plug is only for Automatic transmissions?