I'm in the final planning stages for installing an electric fan on my 3.0 '00. I haven't decided which fan controller to go with but prefer the sending units that thread into coolant passage rather than press into the radiator fins. I've looked all over the motor for additional ports (besides the two on top of the motor near the thermostat) but can't find anything.

While crawling around, I eyeballed the radiator drain. Any chance its a 3/8 NPSH or some other common thread type? It would be pretty slick to replace that plastic drain plug with a brass sending unit. Hopefully someone knows or has spare parts lying around to check.

Thanks in advance and please chime in with other ideas for positioning the sending unit...

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2000 Ranger Trailhead 3.0V6, 5spd, stock for now