A/C Problem HELP!!

DustyMetal01 · July 9, 2019

Alright Gents, I'm new to the forum. My truck is a 2012 Silverado LTZ Z71 and it has the dual climate control and auto climate button. Heres the problem:

About two weeks ago my air quit working out of no where, it would not work at all! Okay, so I replaced the blower motor and resistor and harness, still no air. So, then I replaced the in dash climate control module. The air will work, however it works when it wants to. I can cut the truck on, cut the power on and it wont work, but I'll be d****d if the air works after I've been sweating for a good hour while driving around in this Alabama heat and try turning it on at random! Sometimes, I can take out the fuse to the module and leave it out for a few minutes and out it back in and it work for a few hours with me cutting it on and off as I enter and exit the truck. I finally said to h*** with it and took it to a shop this morning, they called and said that it was the climate control module, that I just replaced mind you, and that they are waiting for a call back from the dealer because the module is a dealer part. I just now got to thinking about something...is there a specific procedure that you're supposed to follow after replacing the climate control module?? Am I missing something??? For the record the resistor did need replacing and I went ahead and replaced the blower motor as well since the old one was starting to lose it's umph and not push air like it used to. So, again...am I missing something here? I've looked and looked, and I'm not the only one with this problem, however no one has the exact problem. I'm really at my wits end guys! I work outside, so yeah I'm pissed right now because I cant escape this dang heat.

sefiroxx · July 10, 2019

Throwing parts at it without diagnosis? Shame on you.

- did the fan motor/blows work fine without ac or with great heat on? Did it work when you pulled out from the housing? Did you check housing, air intake, evap coils when the motor was pulled?

- did you bypass the control module and bring the compressor on yourself (supply 12 v to the compressor via the relay). Did you check the ac high and low pressures?

DustyMetal01 · July 10, 2019

The old module wouldn't ohm out, power was going to it, but it wouldn't work that's why I bought a new one. The new module, however, does have power flowing through it. Like I said, "The air will work, however it works when it wants to. I can cut the truck on, cut the power on and it wont work, but I'll be d****d if the air works after I've been sweating for a good hour while driving around in this Alabama heat and try turning it on at random! Everything seemed to quit/gone bad at once. That's a Chevy for you... The fan wouldn't come on at all after I put in the new blower motor, it wasn't until after I installed the new module that it would start working. I checked everything you named and they were all good. The only thing I didnt think to do was to bypass the control module and bring the compressor (supply 12 v to the compressor via the relay) or ac high and low pressures. *FACEPALM* I've just had it these past two weeks of sweating to death, but I didn't get my truck back from the shop today. I'll get it back tomorrow, I'm not paying for another module.

Edited July 10, 2019 by DustyMetal01