Fan

My 01 chevy prism fan only works on high. what should replace first or any suggestions what isn’t working

The problem could be with the high speed fan relay or with the resistor pack for the blower motor.

The relay switches voltage directly to the blower motor for the high speed or switches the voltage over to the resistor pack for all the slower speeds. So unless you’re able to test which of these components is the actual problem, it’s a shot in the dark to either replace the relay or the resistor pack.

Tester

Blower motor resister. Same thing happened on my 2001 Grand Am… twice. On the Grand Am it is located deep in the passenger wheel well. If you know any contortionists, hire them to do the job. Replacing one of these is the equivalent of playing twister in your car… Right foot ceiling light, Left arm under the passenger seat, etc…

This Prism is mechanically the same as a Toyota Corolla. The resistor pack is under the dash and held in place with a single screw. It should be located right near the fan, just downstream. It should have a connector with 5 or 6 blue wires (w/ different colored stripes) going to it. I purchased one from the Toyota dealer 7 years ago for $35.