A/C runs cool air for about 2 or 3 hours as weather warms up unit turns to warm.

Hello, Have a set of gauges connected when it is not working properly. The high and low pressure readings will indicate to the technician where the malfunction is occurring. If the issue is electronic, they will identify that with a professional diagnostic scan tool. Unfortunately, not a lot can be done with A/C issues at home, especially intermittent A/C issues.