Why doesn't ac blower work on number 5 setting? it is a chevy hd gas engine

Change the. Blower motor resistor. $25 part near the blower. Chevy suvs are famous for bad blower resistors

You have a leak and it should be located and fixed first. But if fill is what you want, you need to locate the fill valve which is on the suction line to AC. Has a valve on it like a tire valve.

Purge manifold of air by opening it a little to let out some gas and then connect to fill valve. Open freon tank valve full and get us much out as you can. Turn upside down and shake heck out of it. Then turn can over, start engine and turn AC on and run engine to about 3000 rpm with AC set for full blast. Keep adding gas until the suction line gets cold and starts to sweat. Then stop. Ac will work as long as it has enough gas - when low the low pressure valve will open and cut off all power to the AC clutch assembly. Then time to refill again.

check for power and ground to rear blower motor. if no power check for blown fuse. if no ground check for bad blower motor resistor for rear unit.

SOUNDS LIKE THE SWITCH & OR THE BLOWER MOTOR RESISTOR, ARE THE PROBLEM WITH THE LOWER SPEEDS. SPEED 5 MAY HAVE ITS OWN FUSE, REFER TO OWNERS MANUAL FOR INFORMATION ABOUT THE HEATER/AC FUSE.

Blower housing resistor fried up.You will have to replace whole blower assembly.

Hi replaced blower resister you done.

sounds like the blower resister

It keeps burning out blower resistors because of the blower motor drawing to much amperage so you will need to replace the resistor and blower motor

If it is working at all then the relay and fuse is good and the problem is either the little vacuum hose on the back of the control switch panel or the panel itself.

the switches are bad. you need to replace the ac / heat / blower switches.