2012SV, AC works great until it has been run extensively in high heat then it gets warm. If I shut it down for a while it will run cold again. Any ideas on cause and solution. Thx, saw nothing on this when searching.
You need to find out what's wrong. Could be low refrigerant, but don't blindly add, the existing refrigerant must be weighed to find out if the charge is correct, and any leaks fixed if low, then correct amount re-added after system evacuation. Low refrigerant could be causing freeze up of evaporator blocking/decreasing air FLOW - is that your true symptom?
Otherwise condenser cooling fan(s) could be the issue - does this happen around town or on the highway???When not operating well, is the CENTER of the compressor turning or stationary? Could be a gapping issue where the magnetic clutch is not holding as things heat up, often a spacer can be removed in that instance. Sometimes tapping - be careful and cautious, danger from moving parts - with a hammer handle to see if that engages can help troubleshoot that, as can a test for voltage at the compressor clutch.