Ford Transit-350 high side AC pressure issue reaching 390 psi with fan operation linked to pressure fluctuations on Ford Transit-350

Some Ford Transit-350 owners report experiencing high side AC pressure reaching 390 psi, which can be attributed to several factors including blocked condensers, overcharging of refrigerant, malfunctioning cooling fans, faulty compressors, or restrictions in the AC system. These issues may be exacerbated by fan operation problems, where the fan does not react at lower speeds but functions normally at higher speeds, impacting the overall performance of the AC system. Additionally, owners are advised to monitor both high and low side pressures alongside output temperature, ambient temperature, and humidity levels for effective diagnosis. When faced with excessively high pressure and non-operational AC, it is crucial to ensure that the system is properly recovered and charged to the correct refrigerant weight as specified on the underhood sticker before proceeding with further troubleshooting.