Either the switch or resister network has failed and needs to be replaced.
When you find out let me know I have same problem replaced blower fan and resisitor did not work. I have a blazer zr2 2002
Yes.
Climate control blower motor was the fix. The part cost 441 dollars.
Common causes, blower motor resistor, blower motor, wiring or controls
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Probably the control unit mounted underneath the relays by the firewall. Get a used one somewhere, but get a new blower (parts store item) to go with it. That might save you from having to buy an other controller.
try a blower motor resistor
Blower motor bad. Blower resistor bad. Switch bad. Fuse blown.
Same problem on mine...I had the blower motor module replaced and it works great.
my 94 explorer wont blow heat
Should under dash on firwall near blower motor.
did your heater switch go out all of a sudden or did some work like high work and low not work? if some worked your blower resister is most likely bad under your glove box