Help electrical mystery

Help needed. I have just completed a major overhaul of my 05 BEW 5spd tiptronic Jetta. I cannot find where the last electrical connector plugs into. Any suggestions are welcomed.
It has 4 wires to a square oval male hub inside a surround . There is an orange rubber sealing ring . The mating connector piece would need to be a shell with 4 pins. I cannot post a picture here, but if you respond to my email address I can send you a picture
Thank you.
waynestrutt@295.ca

Pic below with the plug Wayne is referring to. I don't recognize it, but somebody on here will.

Looks an awful lot like a coolant temp sensor plug.

Just came in and found it. and yes you are correct. On the left rear of the head near the vacuum pump.
Thanks very much, needed a mirror to find it.