What is the first step when diagnosing an AC system issue?

The first step when diagnosing an AC system issue is to check the refrigerant levels and inspect for leaks. This is crucial because the refrigerant is the medium that absorbs and releases heat within the system. If the refrigerant levels are low, the system will not operate efficiently, leading to inadequate cooling. Inspecting for leaks is equally important, as leaks can suggest problems in the system, which could be the root cause of the AC's poor performance.

By starting with refrigerant checks and leak inspections, technicians can determine if there is a fundamental issue affecting system operation. Addressing these concerns upfront helps narrow down the potential causes of the problem, leading to a more efficient and effective diagnosis.

Other actions, such as inspecting the AC compressor, replacing the AC filter, or testing cabin air temperature, could be important but are typically evaluated after confirming the refrigerant situation. This prioritization helps focus the diagnostic process on the most likely issues affecting system performance.