Fan won't stop running

I bought an Acer Aspire 3 A314-21 at a yard sale. The owner said it worked well but needed a new battery as it wouldn't hold a charge. I thought that would be no problem..just buy a new battery. After using it I found that she was right. The battery did charge to 100% but the next day when I turned it on the battery was at 0 charge. After messing with it for a while I noticed that after I shut it off and pulled the AC adaptor the fan continued to run. It ran until the once fully charged battery was now at 0 charge. It did it over and over. I then reset the computer with recovery but the fan still keeps running even when shut off. I had to take the back cover off and unplug the fan and then the battery didn't drain...it stayed at 100%. Something is keeping the fan running all the time. I tried flashing the BIOS to version 1.25...didn't help. I pressed the tiny CMOS button to clear the CMOS to defaults but still the fan keeps running. I used a different m.2 ssd and installed win11 on it but still the fan runs all the time. Updated all drivers but no change. Does anyone know how to keep the fan from running constantly? Thank you....Collieman