What does the:

Coolant Temp Switch Do and where is it? I think it's somewhere on the firewall???

Oil Temp switch Do?

Engine Coolant Temp Sensor Do?

Fan Control Modual Do? I think it's supposed control the fan after the engine is off. Does it do anything else?

 

The coolant temp switch is located right by your thermostat which is located on the tranny side just above your shift linkage. It is a little green plug and you should be able to see it plainly from above. It basically tells your cooling fans when to kick on. Of course that is just one piece of the cooling fan equation but that IS it's major function. The fan control module is under your dashboard right by your left shin when you are driving. It is the other part of the cooling fan equation and receives readings from a bunch of other stuff. The other stuff I am not 100 percent sure so I will not input.