Radiator Coolant Temp Sensor Switch

The coolant temp sensor switch at the bottom of the radiator, does anyone know what degree it will activate at? 180 maybe? Parts house didnt know and neither did the distributor. The tech guy from the actual warehouse for the sensors that Napa gets said and I quote, "We don't know. We just build em."

have to measure the resistance on it i was going to but never go around to it i wanted to use it to run a electric fan

Idk the specifics but that sensor to the best of my knowledge is for the pre-heater plate for a stock carb!In short your stock carb has a wire to plug in the back of the alternator which heats it to prevent iceing.This works in conjunction with the sensor on the bottom of the radiator.My books are not even close to elaborate those details.Tired and hope this helps.

Measure it yourself with your multimeter in ohms setting and digital thermometer, and heat water on the stovetop, keep it stirring (or use magnetic stirrer in the laboratory like I would). As temperature increases, suddenly there will be NO electrical continuity between the two terminals.

Edit: corrected version above, thanks SinCity.

If that's the PTC heater switch, it's closed when cold and opens when warm... Right?

Correct, fixing my post.