Came out to call for a system we performed a repair on not operating again. I was able to locate the issue pretty quickly. System wasn’t transferring power to the outside unit due to ants being inside the contactor that we installed. Customer was a little upset to find out the contactor was the issue again. He wasn’t told about ants probably being the issue the first time around when we had to replace it. I made customer aware that this happens a lot more often around the summer months. Customer had some insect spray and I sprayed around the outside of the electrical panel, and some inside. I was able to clean off the points of contact on the contactor to get the system running again. Told customer that he can give us a call back if the contactor gives him issues, and I would replace it under warranty.