Ursprünglicher Beitrag von: Jeremy Mulcahy-Hill ,
A lot of times with the fans it could be your SMC or PRAM that needs to be reset. These parameters can sometimes go a bit wonky and cause all sorts of system issues, however I see that you have already attempted this. Where did you source the fan from? The laptop fans are typically controlled via software with readings from a thermal sensor, however if the fan does not have the exact wiring that the previous did, it will instead run full speed as there’s nothing controlling the voltage to it.