1. Compressor Not Engaging: Ensure that the air conditioning compressor is actually engaging when you switch on the AC. Check for any issues with the compressor clutch or its electrical connections.
2. Faulty Idler Pulley: The idler pulley, also known as the tensioner pulley, helps maintain proper belt tension for the air conditioning system. If the idler pulley is faulty or seized, it can affect the proper functioning of the AC and prevent the engine rpm from increasing.
3. Slack or Broken AC Belt: The air conditioning belt transmits power from the engine to the AC compressor. If the belt is loose, worn out, or broken, it may not be able to effectively drive the compressor and could result in the engine rpm not increasing.
4. Throttle Body or Idle Air Control (IAC) Valve Issue: The throttle body or IAC valve regulates the air intake and maintains idle speed. If there are any issues with these components, they can prevent the engine from responding properly to the increased load from the AC and cause the rpm not to increase.
5. Engine Vacuum Leak: A vacuum leak can cause the engine to run lean and affect its overall performance, including the response to increased load from the air conditioner. Check for any leaks in the vacuum hoses or components.
6. Faulty AC Pressure Switch: The AC pressure switch monitors the refrigerant pressure in the air conditioning system. If the pressure switch is faulty or out of adjustment, it may not properly signal the engine control unit (ECU) to increase the engine speed when the AC is turned on.
If you've checked these potential issues and the engine rpm still does not increase when you switch on the air conditioner in your Daewoo Matiz, it's recommended to consult a professional mechanic for further diagnosis and repair.
