So a few days ago, I installed Raspbian Bullseye on my Raspberry Pi 4, and now the case fan (pin 4) is running 24/7
Even when the fan is disabled, the GPIO 14 pin is unplugged, or the system is turned off, the case fan still spins
Also, I can't let the fan run 24/7 because its very noisy and it can wear away
I don't have a case fan, but you can configure it to be temperature controlled. (I use another fan, and it is simple to setup - I don't use the TxD pin to control it as this is used by UART.)
If you did a fresh install of Bullseye you will NEED to setup again.
See https://www.raspberrypi.com/products/raspberry-pi-4-case-fan/ which says
"Once you have connected your fan, by default it will be on whenever your Raspberry Pi is running. You can configure it to turn on only when your Raspberry Pi reaches a temperature that you choose."
You can choose to use another pin and temperature.
