I have a 2007 Envoy Denali that stalls after driving for at least an hour.

What is your question?

The process seemingly speeds up if I run the A/C and it will die after 30mins. When i attempt to restart the automobile the ignition will keep turning itself even after letting go of the key. If i allow the vehicle to sit for 30 mins to an hour then it will restart. I've had it to the repair shop 4 times in the past 2 months, they replaced the ignition switch to no avail. What could be the issue here? Also the check engine light comes on after it stalls out I had it analyzed with a code reader and I don't have the specific codes but i remember it said Bad ignition switch(which they replaced) and ECM & PCM low voltage . Any information/help would be greatly appreciated. Thanks in advance.

What makes this problem better or worse?

Running the air causes the issue to happen faster.

How long has your 2007 GMC Envoy had this problem?

3-4 weeks