Madeline, I did find that the contactor inside of the unit on the roof, (s/n ending 934F 45N), is worn, contacts are pitted and there are signs that it has been arcing. This would cause an intermittent lack of cooling that was observed earlier in the week. Below is the estimate for the replacement of the contactor. This is a time plus material estimate. The materials will be the contactor and any new electrical connectors needed to replace the contactor. The cost for the materials is $68.89. The time to replace the contactor is estimated at 1.5 hrs at a rate of $139.00 per hour. After the replacement the contactor will be tested for proper function. A one year parts and labor warranty will apply to all work listed above. Thank you, Jon