| A/C SYMPTOMS CHART |
| High-pressure | Low-pressure | Clutch cycle times: cycle | Clutch cycle times: on-time | Clutch cycle times: off-time | Fault cause/action |
| too high | too high | A/C compressor running constantly | A/C compressor running constantly | A/C compressor running constantly | Air conditioning condenser contaminated |
| too high | normal to too high | A/C compressor running constantly | A/C compressor running constantly | A/C compressor running constantly | Engine overheated |
| normal to too high | normal | A/C compressor running constantly | A/C compressor running constantly | A/C compressor running constantly | Air or contaminants in the circuit. Too much refrigerant in the system |
| normal | too high | A/C compressor running constantly | A/C compressor running constantly | A/C compressor running constantly | Fixed orifice tube. O-rings damaged or leaking |
| normal | normal | too slow | too long or constantly | normal or not at all | Contaminants in the circuit or too much refrigerant oil |
| normal | too low | too slow | too long | too long | A/C low pressure switch faulty |
| normal to too low | too high | A/C compressor running constantly | A/C compressor running constantly | A/C compressor running constantly | A/C compressor faulty |
| normal to too low | normal to too high | A/C compressor running constantly | A/C compressor running constantly | A/C compressor running constantly | Low-pressure line blocked |
| normal to too low | normal | too fast | too short | normal | Evaporator blocked |
| normal to too low | normal | too fast | too short | normal to too long | Air-conditioning condenser, fixed orifice tube or high-pressure line blocked |
| normal to too low | normal | too fast | too short | too short | Not enough refrigerant in the system |
| normal to too low | normal | too fast | too short | too long | Evaporator input line blocked |
| normal to too low | too low | A/C compressor running constantly | A/C compressor running constantly | A/C compressor running constantly | Low-pressure line |
| – | – | irregular operation or inoperative | irregular operation or inoperative | irregular operation or inoperative | A/C low-pressure switch contacts are dirty or permanently open. The connector of the A/C low-pressure switch or of the A/C compressor clutch is dirty or damaged. |
