Heater fan not working

Hello,

An inoperative blower motor could be due to a bad relay, faulty wiring, blower switch or the motor itself can be bad.

https://www.2carpros.com/articles/blower-fan-motor-works-on-high-speed-only

First check the relay. The Blower Motor Relay is located behind the bottom right side of the instrument panel (see diagram below).
Look for any corrosion or burn pins.

Here is a guide on how to test the relay:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

If the relay is good, check to see if there is power to the blower motor. If there is power but no motor operations, then it could be a bad motor.

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.