Ved

Hi Guys,

My radiator fan switches on at around 185 Degrees Fahrenheit, which means that it is basically working constantly. The switch is an AC Delco D1852B - the switch is new, as the the coolant temperature sensor and the thermostat. I believe that the radiator fan is meant to switch on at higher temperatures (~210 or more Degrees Fahrenheit). Does anyone know how I could correct the issue so that the fan switches on the at temperatures that it should. Is this a switch issue, or something else?

Any help would be greatly appreciated.

Cheers,

Ved

WVZR-1

How have you arrived at what you believe the temperature? What year? For most years that switch is used for the AUX FAN or maybe to 'over-ride' a primary fan for other years. Year and how wired dictates how that switch is used!

Hot Rod Roy

I have that same CTS in my '84, and it cycles my radiator fan on and off just fine. I haven't tested the on-off temps of my sensor with an accurate thermometer, but the specs I've been able to find list the on-off temps at 215 on and 200 off. All specs have a +/- tolerance, but your reading seems a long way off those numbers. As WVZR-1 asked,"how did you determine your numbers?"

JoBy

A/C pressure switch will also start the cooling fan.

This is for 1984: