Running the air conditioner and headlights simultaneously typically should not damage the alternator. The alternator is designed to handle the electrical load of various components in a vehicle, including the air conditioner, headlights, and other electrical systems.
However, it's important to note that both the air conditioner and headlights draw power from the vehicle's electrical system, which is supplied by the alternator. Running multiple electrical components simultaneously can increase the overall load on the alternator, potentially affecting its performance.
In most cases, the alternator should be able to handle the combined electrical load of the air conditioner and headlights without any issues. However, if you frequently experience problems like dimming lights, a weak battery, or difficulty starting the vehicle, it's possible that the alternator may be struggling to meet the increased demand.
If you have concerns about the electrical system in your vehicle or suspect alternator issues, it's recommended to have it inspected and tested by a qualified mechanic. They can diagnose any potential problems and determine if any repairs or replacements are necessary.