I have seen this plug on a few trucks but i have not been able to locate what it is meant for? It is right under the door for the interior fuse panel.

 

It's for trailer brakes

 

Well that is what i thought it was till i found a plug on the side of the OBD II port that everyone says is for the trailer controller. The plug in the picture only has 2 wire going to it.

 

The one on the side of the obd2 port is the electric brake controller plug. I have no idea what that plug is.

 

My truck did come with the factory air load leveling system. Could this be part of it?

 

I'm not completely positive but my last truck had an electric sliding back glass and that might of been where it hooked up

 

Can't be. The plug for the rear power slide window is directly behind the HL switch.

 

I'm really curious now. I just went and looked at mine and I have the same thing

 

It's 2 wires? What colors are the wires? I'm betting on it being a courtesy light add on plug for under dash lights, like in the KR's and such. If one of them is blue with red, it is a light circuit. If it is, you should have another plug on the passenger's side, unless they use only one harness across the lower dash for the c/lights.

 

The plug has a Red w/ Pink stripe wire and a Green w/ Black stripe. Other than testing for 12v i do not see if it has any function. And i checked i do not have one on the passenger side, just a suspension test port that looks like an EEC test plug.