A/C Diagnostic Process
When a customer presents an A/C concern, do the following procedure to identify the cause of the problem.

1.
Confirm the type of concern.
If a customer complains about an A/C noise problem, do the A/C system noise check.
If a customer complains about an A/C performance problem, go to step 2.

2.
Do the A/C system inspection and repair any problems. If no problems are found, then go to step 3.

3.
Recover the refrigerant from the A/C system and measure the refrigerant charge from the A/C system using a recovery/recycling/charging station that meets SAE J2788 standards.
If the refrigerant charge is within specifications, evacuate and recharge the system. Then go to step 4.
If the refrigerant charge is significantly under specifications, then go to step 5.
If the refrigerant charge is significantly over specifications, evacuate and recharge the system. Then go to step 7.

4.
If vent temperature or suction/discharge pressures are not within specifications, diagnose and repair the A/C system as needed. Then go to step 6.
If no problems are found, the A/C system is operating as designed and the A/C diagnostic process is complete.

5.
If any leaks are found, repair the A/C system as needed. Then go to step 6.
If no leaks are found, go to step 7.

6.
Evacuate and recharge the system. Then go to step 7.

7.
Do the A/C system test to confirm your repairs.
If vent temperature or suction/discharge pressures are within specifications, the repair is confirmed and the A/C diagnostic process is complete.
If vent temperature or suction/discharge pressures are not within specifications, a problem may still exist. Return to step 1 and recheck your test procedures.