Ka24de s14 question

[shotcaller1681]

Hey guys i have a pretty easy question that i cant figure out
i just bought a s14 with a ka24de(stock) and the guy has a hacked up wiring harness and there is no plug for the engine coolant sensor(the red one) but there is a big empty grey plug further down the harness that has nothing plugged in to is that just a junction for the wires with the plug on it? if so i need to know which wire goes to which port of the sensor so i can cut the plug and wire it up thanks!

[shotcaller1681]

http://i97.photobucket.com/albums/l235/shotcaller1681/Mobile%20Uploads/image_zps7gvroxl6.jpeg (http://s97.photobucket.com/user/shotcaller1681/media/Mobile%20Uploads/image_zps7gvroxl6.jpeg.html)

[shotcaller1681]

That's a picture for reference and it looks like it's coming from the harness and I've Deloomed my harness pretty far up and can't find any cut wires so I'm gonna have to go all the way to the ecu
Is that grey plug maybe for the AC?