The higher lower knob blinks heat and air hardly comes out

Have you tested the blower motor?

How do i do that?

Once you find it there should be a plug on it with 2 pins....positive and negative.....give it power directly to and from the battery

Usually under the dash on passenger side....that will either tell you that the motor is bad or if it's in the switch/wiring (assuming you already checked fuses)

Ok ty