I have been working as an A/C repair Tech for a few years now, and we normally run into the same problems every summer. Our A/C repairs triple during the months of June and July, because of the scorching outdoor temperatures. When the outdoor temperatures become extremely hot, there are a couple of typical repairs that we see. Most of the time these repairs are bad contactors or bad capacitors. There is an enormous amount of energy flowing in your A/C component, and a 20 degree jump in the heat index is a big deal. This Heatwave can have a detrimental effect to your A/C component. I probably fix one or two capacitors each week, during the hot summer months. Another common problem that we fix, is the fan motor. The fan is located behind the air conditioner, where the temperatures are extremely hot. The fan motor can be a very expensive repair, sometimes costing in excess of $400. The biggest problem is compressor failure, and that always means replacement. The compressor is the integral part of your A/C system. The compressor is like a car motor, and the whole system cannot run unless the compressor is functioning properly. Unfortunately, the air compressor can be a very expensive part to replace. We always recommend replacing the entire HVAC component, if the compressor is no longer under warranty. The cost to replace the entire HVAC component, is usually only a fraction more than replacing the compressor alone. For that specific reason, we usually recommend a new high SEER energy efficient system.