Hi, I have 01 tahoe 2WD 5.3L the rear a/c made noise for awhile before it stopped working,i need help on finding out what the problem is. i checked the blower to a battery and it worked, i don't know if the auxiliary heater resistor is bad which connects to the blower,i get 12v on the orange wire going into the auxiliary heater resistor but none on the purple wire going to the blower..
Any help would be greatly appreciated.. Thanks

 

I had a similiar issue with my 03 TB. I'm guesing the ac systems are generally the same. The 12v is always there, the system grounds the other wire to turn the blower on. You can try grounding the ground wire (not the 12v wire) on the input of the resistor to make sure the blower comes on. I would suggest you get the schematics for your system if you feel comfortable troubleshooting to that level. There are several sites that you you can the info from for a small fee. I don't think I can suggest the one I used so I won't. I will attach the thread for my problem and it may help some to read it. I have a 06 Tahoe as well so if I can help with looking at something on it for comparision I will try to help further. I know our trucks are several years apart but other than auto vs manual they are probably similiar. That is just an opinion, I do not know that for sure.

https://chevroletforum.com/forum/tra...working-42019/

 

it was the auxiliary heater resistor that was bad

 

Just an FYI to add to post. I had a similar experience with my 04 2500 burb with the rear fan not blowing on high. I had only 3-6 volts supplied and traced it back to a bad connection in multi-pin socket located to left of drivers left foot behind panel. I cut off both sides and joined wires outside plug and all is well. GM seems to need better connectors.