Where is the AC blower motor resistor, for the front blower motor, located on an 02 Acura MDX?
The normal location is in the HVAC duct near the blower motor. Sometimes the resistors can be difficult to access.
Usually you can locate the speed control by following the wires from the motor since they tie to it. Your vehicle may not use resistors to change the motor speed. It may have a solid state controller. If you have a variable speed control rather than a few selectable speeds then I would say that is the case.
Edit: I just looked at some data for your vehicle and it appears you do have a solid state controller. There is a blue/red wire between the motor and it. It should be mounted on the ducting near the motor.