Chosen Solution
The air in the backseat of my 2002 Tahoe doesn’t not give any air. The front works great but the vents above the backseat and rear don’t give any air. The lower vent in the rear works too just none of the vents on the roof of the car.
I would start with the fuses. There is a 30 amp fuse in the fuse block under the hood. Another fuse is in the interior panel. I believe it is titled IGN 3. If those are not the issue you may have to access the blower motor in the rear of the SUV.
