The problem is the ignition switch. The ignition switch controls power to the hvac system and the cruise control on the same circuit. Have seen this problem a few times in the past year. You can confirm this diagnoses with a test light, check the cruise fuse that is located in the drivers side fuse box (where the drivers door and dash meet on th dash). Use a test light when the system is inop, if the test light does not light up, then there is no power from the ignition switch.
Let me know if you have any more questions on this issue.