120v outlet pinout question.

[JustARam22]

So I did a center seat console swap, the console I bought can with 2 120v outlets in it. I am adding an aftermarket power inverter and was curious if anyone new the pinout for the factory power outlets. They are 4 wires instead of 3 which is a bit confusing.

Should only be neutral, ground, hot... What's the 4th wire.

 

[jsalbre]

It has an LED that lights up to show that the outlet is powered up.