RepairPal is your advocate for car care advice and guidance

Q: My heater fan used to work on the 4 setting and now doesn't work at all. Any advice? on 2004 Chevrolet Trailblazer

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
My heating/AC fan was working on the 4 setting and now doesnt work at all. I checked the 35 fuse under the hood and that was good. I also checked the HVAC fuses under the back seat as well. All good. I am wondering what the issue may be and the cost of repair. And if its the resistor behind the glove compartment, where exactly is that located. Thanks
If you get no blower at any speed, check for voltage at the large lead going to the blower motor. I believe it would be purple on this vehicle. If you have voltage here, Check the ground wire. If both are good, the blower motor is bad.
Just re-read your post, and you previously lost all low speeds but still had high? If so, the increased current demand from the failing motor caused the blower resistor to fail first, causing loss of all low speeds. Then the blower motor finally died.

So you will probably have to replace both items.
I had this problem as well and I changed the blower resistor and that fixed the issue. The resistor is located under/behind the glove compartment. It is a lower cost fix than the fan. I would give that a shot first.
Didn't find what you were looking for?