ok i has been a while since i have posted on here but i feel that this site has the most knowledgeable people on it so here it goes. I have a 2000, ext cab, 2wd NBS silverado 1500 5.3l. When i turn my A/C on, setting 1 and 2 dont work(meaning no air comes out of the vents) then when i turn the dial to setting 3, it starts blowing lots of air. This is progressive up until the final setting of 5. so basically 1 and 2 dont work, yet 3,4,& 5 work as they should. Any ideas? this is not intermittent meaning that this ALWAYS happens. Also, when i have the air on and i go around any turn, i get a fan squeaking noise out of the general vicinity of the blower motor. it sounds as if the blower motor blades are hitting the blower motor casing. Do you think this could be part of it? i dont want to pull my dash apart unless i have to because it seems like a royal pain in the butt to do(although it might be inevitable). someone told me its an electrical problem and i would take it to the dealer to get it fixed but i have tried that before and there fancy $40,000 electrical diagnosis machine didnt work and i was out $90. what a waste of money. Thanks again for any input.

 

Probably just the switch. If it was the blower motor resistor I would think every number would blow at full blast. Your problem sounds like the 1 and 2 contacts are dirty or just malfunctioning.

 

well how do i check/clear that?

 

Switch is probably fine. The blower motor resistor is much more common. Also check to make sure the connector to the resistor is not melted. There was a problem with some of the connectors that would require replacement of the connector and resistor.

 

when my blower resistor died 1 and 2 didnt work but the rest did

 

I lost 5 but had 1 through 4. What happens is the Blower motor will start to pull to many amps killing resistors in the resistor blocks. You need to replace the blower motor, and resistor block. You need to do it quick or else you will have to spend another 100 bucks for the resistor block harness connector from GM do to it melting.

Orielly's is where i got mine, They make 2 different resistor blocks (1 with 2 mounting holes, 1 with 4 holes), and 2 blower motors, (one with screws holding it in place, and one that is a spin lock type)

I am 100% thats whats wrong. I have fixed my truck, and about 15 other trucks with the same complaint, "i dont have all speeds on my blower" or "i dont have any air".

Dustin