What's the Thermosensor????
 

What exactly does the thermo sensor at the back of the water pump housing do? there are two sensors on my 89TII and i would like to know what they are for. I disconnected one of them ( i think it's the A/C sensor of some sort) and ran the thermostat to my E-Fan. I haven't experienced any problems yet. this was over 6 months ago.

there are 2 plugs at the back of the water pump housing on the 89-91. the thermosensor is for the ecu and is important. the other one is a switch to turn on the aux fan and to run the 3000rpm startup.

On my '92 TII, there are actually two air thermosensors (intake and turbo), and one water thermosensor. The intake thermosensor isnt very functional, but the other two are crucial and essential. I wouldnt disconnect any one of them...

This url http://www.howstuffworks.com/fuel-injection.htm and click where it says *engine sensors*. The water thermo sensor is supposed to be one of the more important sensors for the fuel injection system, along with the pressure or boost sensor(map sensor). The water one is the larger green one. Then you've got an air temp sensor in the air flow meter and also the side of the dynamic chamber.

Go to this site http://www.iluvmyrx7.com/Technical_I...ice_manual.htm and look in section 4B, page 4B-46 and it will tell you how to check out your water thermo sensor.

Yeah i got rid of the smaler white/grey one. I haven't had any problems with the car, and this was done back in april. it starts fine and doesn't over heat. the 12" fan still comes on when i turn on the A/C. So i guess i didn't screw anything up. Someone just told me that it was crucial to have all the sensors in your car. I know the water thermo sensor is important, i didn't really know what it did? just that it's needed. But the other one according to the shop manual did seem like i would need it.

does your car still rev to 3000rpm at cold start up?

The A/C will probably turn the aux fan on. but it won't turn on at 220F or whatever it's set at as your backup fan.

Yes it still revs to 3,000 rpms just not everytime. I guess the fan doesn't do much more than what my spal can pull. 2.300 CFM