High (Discharge) Pressure | Low (Suction) Pressure | Component — Causes |
|---|---|---|
High | Normal to High | Condenser — inadequate airflow. Engine — overheating. |
Normal to High | Normal | Refrigerant overcharge — air in refrigerant. |
Normal to Low | High | A/C Compressor — low performance. |
Normal to Low | Normal to High | A/C suction line — partially restricted or plugged. a |
Normal to Low | Low | Low refrigerant charge — leak in system. A/C suction line — partially restricted or plugged. b |
Erratic Operation or Compressor Not Running | Ambient Air Temperature (AAT) sensor — poor connection. A/C pressure transducer — poor connection. Evaporator temperature sensor — poor connection. Low refrigerant charge — leak in system. | |
Additional Possible Components or Causes Associated With Inadequate Compressor Operation | ||
Compressor drive belt — loose Compressor clutch — slipping Clutch coil open — shorted, or loose mounting Control assembly switch — dirty contacts or sticking open Clutch wiring circuit — high resistance, open or blown fuse Compressor operation interrupted by engine computer | ||
Additional Possible Components or Causes Associated With a Damaged Compressor | ||
Incorrect clutch air-gap Suction accumulator — refrigerant oil bleed hose plugged Refrigerant leaks | ||
a Low pressure reading will be normal to high if restriction is downstream of service access valve. b Low pressure reading will be low if restriction is upstream of service access valve.
Copyright © 2016 Ford Motor Company
2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.