It looks like my car has 3 coolant temp sensors. I need to know what each of them do, so that I can check and replace them if they are bad. Below is a picture of my car's 2.3 8v engine's front side(1st pic - thermostat housing, 2nd pic - engine fan)
I have numbered parts that look like sensor. The sensor #1 is more complex. It has 4 wires coming to it. The others just have 1 wire.

Thanks

Attached Thumbnails

 

__________________
1989 230E, 8v, 166.000 km, updated to 94/95 trunk & hood
2002 Daewoo Nexia 50.000 km
Sold:
1987 VW Jetta GLE 16V, Recaro seats
1982 Volvo 240 DL (lovely car!)
and few more american cars.