Your resistor may have failedOn another note, my heater blower only works when its on full blast now... not sure if anyone else has had this issue and how they fixed it? I've had issues with the vents anyways. The only thing that seems to work before was the floor vents and the side window defrost vents. It didn't default to the windshield defrost vents like I've heard its supposed to do. When I shift the selectors, it sounds like it all moves, but as soon as I turn up the air, you can hear a vent slap shut and air only comes out specific vents. I haven't tried pulling it all apart... seemed like a pain and its only cold for a few months in Louisiana.
Car Control Heater Motor Resistor Module Blower Compatible with Jeep Wrangler TJ https://www.amazon.com/dp/B01MXHL7ID/?tag=wranglerorg-20