Now for my first question - a friend just asked if I’ve ever heard about an A/C system needing to re-learn how to cool after replacing a battery. He just had his 2004 Yukon (with climate control) battery replaced at Sears, and the A/C now blows hot air. The Sears tech told him this was normal, the climate control needed to ‘re-learn’ how to follow the temp settings. Huh???
That sounds like a know-nothing tech trying to duck liability. He probably blew a fuse or fusible link while changing the battery.
On many GMs, the blend door actuator has to be calibrated. When you disconnect the battery long enough, the calibration is lost and must be re-learned. Some models require a scan tool to start the process but I believe your Yukon can do it automatically. Turn all A/C controls off. Disconnect the battery for 2 minutes. Reconnect the battery and start the engine. Do not touch any A/C controls for 2 minutes. The system will exercise the blend door, running it between stops and this will complete the re-calibration. If it still blows hot air, then you have a different problem.
Thanks TT, I’ll let him know.