Any information on 1972 280SE overheating problems? Is the axillary fan just for the AC? I've re-cored the radiator, replaced the thermostate, pressure checked everything and it still overheats. Any suggestions?

My Dad still has his 71 280SE...how do you like yours?

Sorry for going off on another tangent...I'm fighting with overheating on my 300E as we speak.

All I know is that I can keep temps under control if I DON'T turn on the A/C. It's HOT in Texas, so that is really not an option, but at least I can rule out some things.

Other things to look at is the radiator cap, coolant mix ratio, or air in the system (not likely unless you just did a flush and refill recently). You just had your radiator re-cored, so you can rule out dirt in the cooling fins. Check the ones for the A/C radiator, just to make sure.

As with you, I haven't found anything in the Haynes manual that specifically states whether or not the aux fans work exclusively for the A/C or not. But like you, I've started pointing the finger at the temp sensor (also it's the only part of the cooling system that I haven't replaced). If you unclip the wire from the sensor, the fans should run at max speed.

I'm still testing the system to see what gets the fans going...

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2016 Mustang (32K) - Daughter's car