I have a 1993 Honda accord 10th anniversary edition and the radiator fan won’t come on when the car is running but the moment the car is off it turns immediately on.
My temp gauge works just fine, and I’ve replaced temp sensors and thermostat, relay, and fuses but the problem persists.
Not sure where to go any direction and help is greatly appreciated. Thanks in advance.

 

Which fan? FWIW, have you looked at the "B" fan switch (at the water outlet - not the thermostat)? I forget at the moment which fan was running when the key was extracted from the ignition (driver side I think), and here's a thread on this site with more background.

Pulling the connector at this switch stopped the fan, though I was careful to reconnect before I drove the car.

An OEM part number appears available (37773-PT3-505), but at 5x the cost I took a chance and tried the Beck/Arnley 2011608 with success.

 

I would assume switch “B” works fine as the fan turns on after the car has been shut off. The car will start to over heat whenever I’m stopped at a red light or such. Also it is passenger side fan that is not working.