What if the fan in your 97 Maxima only has off and high settings for the HVAC Could this be the blower motor resistor the fan switch or something else?

Yes this is generally caused by the Heater fan resistor. Its housed in the fan housing itself, and is quite easy to get to. just remove the clove box and you will see a connector with four wires coming from the bottom of the fan housing. If you disconnect the plug, and remove the 2 screws the unit will come out easily. it is merely a flat printed circuit board that inserts into the fan cavity. Its a matrix of low value resisters that are switched into series with the fan itself, and by being in the airflow of the fan is kept cool. it also regilates the fan speed due to it heating and cooling with the blown air. Can be anything from $20-100 depending on where you buy it from. It does not seem to be repairable as i tried to with a soldering iron. and it jaust made it worse.

A burned out resistor can be the result of a failing blower motor. So if the new resistor burns out in a short time, replace the motor also.