Thermostatic switch turns on at 185 degrees and off at 175 degrees; Thread size: 3/8-18NPT; 1/2 NPT to 3/8 NPT adapter provided Weatherproof Fan Relay Kit w/Thermostatic Switch 185F On/175F Off Part... Installing air conditioning to your hot rod? Need a cooling fan relay to operate off of a thermostatic switch and when your A/C is on? The dual activation cooling fan relay kits by Painless Performance are exactly what you need. Painless Wiring PW30127 Fan Relay With Thermostatic Switch Chev/Holden Thermostatic Switch 185°F On 175°F Off For 1992-1995 Honda Civic Engine Cooling Fan Motor Relay 4 Seasons 1993 1994 Dual Fan Relay Features simple to use Posi-taps for the ignition and A/C compressor connections Painless Wrg 30112 Coolant Fan Temperature Switch Features simple to use Posi-taps for the ignition and A/C compressor connections. Only a few minutes for the installation and your cooling fan will come on when the engine reaches the preset temperature of the thermostatic switch mounted in the engine head or when the A/C is turned on.