What would a bad coolant temp switch/sensor cause besides turning the cooling fan off and on? The switch on the front of the block was causing my fan to go crazy. I'm replacing this one but just curious what else these do for the engine.

 

If I'm not mistaken, it won't do anything. The front one controls your fan, the single wire is your sender unit (to the gauges in the dash) and the wire closest to the firewall tells the ecu what's goin on. What's the issue?

 

Wrong.

The front ECT on the upper radiator neck gives info to ECU to turn condensor fan on/off while the back ECT located on the thermostat housing control's the radiator fan.

 

Are they both the same to replace (part #)?

 

Found it. They're not.