Depending on the model the thermostat sending unit triggers the fan on at 185 f.
Electric fan temperature sending unit.
And off at 175 f.
Electric fan thermostat in line sending unit 180 degrees f on 165 degrees f off 10 an inlet outlet kit 2 part number.
Buy fan thermostat temperature switch with 3 8 pipe thread 185 to 175 degree electric engine cooling fan thermostat temperature sensor switch fits 10 12 14 16 fan with pipe thread.
Pre wired connector plugs into fan connector and the red wire is routed to the relay via an inline crimp connector.
Amazon s choice for electric fan sending unit partssquare 3 8 185 degree on 170 degree off radiator cooling fan thermostat temperature switch kit compatible with 265 283 305 400 347 352 360 390351m 400m 273 318 340 360 361 383 400 engines.
A toggle switch can be wired into the system to manually override the cycling of the fan.
And off at 165 f.