A loose cap on your air conditioning compressor would that keep the unit from wo

Hi, my name is Devin. I am an auto repair expert with the Car Genius team here at RepairPal. So sorry to hear you're having trouble with your vehicle. Loosening a refrigerant service port cap on your A/C system should not affect system performance. These caps are just to keep contaminants away from the Schrader valve that actually contains the refrigerant. If you did not notice refrigerant escaping from the system, I recommend reinstalling the cap. If your compressor is not working, the issue most likely lies elsewhere. If you need more advice, have any other questions about your vehicle, or would like to get connected to a RepairPal Certified shop near you, we have you covered. Give us a call at 877-913-1554, and we will happily help you out!