Gas and Oil Home Heating Furnaces - Central Air dims house lights

When I turn on my central air unit our house lights dim briefly (blink) on a pattern (every 7 to 10 sec.). I checked the breaker box and the breaker is a 30 amp that will lightly buzz at the same time the lights dim. The AC has worked great all summer until this past week. The furnace and blower are new (five years) but the AC unit outside is old. Could this be more electrical versus AC?

I have added some additional lighting inside the house but I have turned that breaker off to test but the dimming still occurs.

Thanks.

Your compressor is trying to start but can`t. It is cycling on its internal overload. Many possibilities. Could be a bad capacitor, burnt wires, locked up, bad windings, ect. You could visually inspect your wiring and capacitor(bulging or leaking fluid) with the breaker off. If the wiring & cap is ok, you will need a pro and probably a new unit. Good luck.