im pretty sure that the sensor on the back of the water pump with the green connector is connected correctly, but just under it to one side is what looks like a circular connector with a hole in the middle and i dont have it connected to anything, should it be??

 

Found on Jspec motors, it is a sensor, but sounds like your's has the wires ripped out.

 

is it neccessary or can i just leave it unplugged, i have the emmissions removed and the omp removed anyways.

 

http://mazdatrix.com/pictures/o-elec...FanSensorB.jpg

Is that the sensor you're speaking of? If so, it's a fan switch sensor. I replaced that sensor with an aftermarket water temp sensor and gauge. No problems so far.

 

thats it exactly awsome, but what do you mean fan switch i dont have electric fans just a clutch fan.

 

any thoughts??

 

Some have stock electric fans (my '91 does) they are in front of the radiator

 

Turbos and some automatics have a factory supplemental electric fan.

And that sensor is not on the back of the water pump (as the thread title might suggest) on any of the S4 models, but rather it is on the thermostat neck, so next time you should include model and year.