With great success took my motor out to do a clutch and header, and repair a broken manifold stud. I put the car back together and it is running fine.
I found this connector, it is on a short leash, and I can't figure out where it goes to. I have an R53 6 speed manual.

It comes out of the octopus harness near the thermostat. It is about 7" shorter than the front headlight sensor. It is a 3 conductor connector, and the colors are:

black with green stripe
brown with black stripe
black with white stripe

> it ain't the coolant sensor by the Tstat housing, that is already plugged in and working.

> it is not the reverse switch, that is working.

Clues?

 

Rear T Map sensor near the thermostat ? Are you getting a code or anything. Zoom out a bit.

 

Found it !!
Goes to pressure switch for a/c line that I gutted. I put the old sensor back in and me fan stopped running high speed when cold.

 

Had that happen too when I gutted mine, was so happy when I found out what it was haha. Was scared when the fan was staying off