Maytag side by side fridge has a noisey fan but I don't know where it's located?

Usually when the evaporator fan starts making noise it's due to the fact the motor is shortly going to burn out. You'll be replacing this motor soon enough to know where the fan motor is located.

There are two fans: one inside the freezer behind the cover over the coils and one on the bottom for the condenser. You probably need to clean the coils by washing them off and then oil the motor. These condenser fan motors frequently have no oil hole so you have to pierce aluminum cap on the top of it with an ice pick or drill. It is filled with felt and soaks up the oil. If it has been too long then your bearings may be ruined and you will have to replace the motor. Just make sure to get the rotation correct. You will have to remove rear cover on unit to get at everything, but always replace it because the unit relies on the cover to route air through the coils. Without the cover it will burn up the compressor very fast. Clean the coils every six months. You can buy a special brush to get in there to clean them at appliance parts stores and I think Sears sells them, too. Good luck. DrTom4444