1. Low refrigerant level: If the refrigerant level in your air conditioner is too low, it can cause the unit to work harder than it needs to, which can lead to electrical problems and flickering lights.
2. Electrical issues: There may be an electrical problem with the unit itself, such as a loose connection or a faulty capacitor causing current fluctuations that dim lights.
3. Overloaded circuit: The circuit that the air conditioner is plugged into may be overloaded, causing the lights to dim whenever the air conditioner turns on.
4. Faulty contactor: The contactor is a switch that controls the power supply to the air conditioner compressor. If the contactor is faulty, it can cause the air conditioner to turn on and off repeatedly, which can lead to flickering lights.
If you are experiencing this problem, it is best to contact a qualified HVAC technician to diagnose the cause and perform the necessary repairs.