• Increased load on the engine. When the air conditioner is turned on, it puts an extra load on the engine. This can cause the engine to work harder and run rough.
• Loss of vacuum. The air conditioner system uses vacuum to operate. When the air conditioner is turned on, it can create a loss of vacuum in the engine. This can cause the engine to run lean and misfire.
• Refrigerant leaks. If the air conditioner system has a refrigerant leak, it can cause the engine to run rough. Refrigerant is a coolant that helps to keep the engine cool. When there is a refrigerant leak, the engine can overheat and run rough.
• Electrical problems. Electrical problems can also cause the engine to run rough when the air conditioner is on. These problems can include a faulty alternator, a bad battery, or a loose wire.
If your engine is running rough when the air conditioner is on, it's important to have it checked out by a qualified mechanic. They can diagnose the problem and make the necessary repairs.
