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HVAC, some days it works fine others not at all

2004 Chevrolet Tahoe that has the dual climate control features. Some days the A/C blows cold on one side and hot on the other with it set on the coldest setting. Another day it blows cold on both. Then you guessed it a few days later it goes back to blowing hot on one side and cold on the other. Any ideas?

Have it serviced. Sometimes A/C problems can be cured with the proper level of refrigerant. Or you can go to the parts store and get an R-134A charge kit and do it yourself. If you choose the kit make sure you get one with the gauge so you don’t overcharge the system.

Sounds like a bad blend door actuator in the dash. Sometimes disconnecting the battery for a little while will reset them; otherwise it needs to be replaced. The dashboard needs to come out to perform the repair. A GM dealer will have a scan tool that they can use to help diagnose the problem.