2004 Ford F150 AC Not Working with Code P0645 Issue

The 2004 Ford F150 can experience problems with its air conditioning (AC) system, particularly when code P0645 appears. This code signals an electrical issue impacting the AC system's performance. Common causes in the F150 include AC compressor clutch failure and faulty pressure switches, both of which can result in the AC failing to produce cold air.

Even if the AC compressor and relay are new and the fuse is confirmed to be good, the problem may stem from the AC pressure switch or compressor clutch wiring. For instance, bypassing the relay might power the compressor, but if no cold air is produced, it could mean the clutch is not engaging properly or the refrigerant pressure is too low to activate the system.

To address this, inspect the AC pressure sensor and the clutch coil for electrical continuity. It is also important to verify that refrigerant levels are adequate and that all wiring connectors are securely attached. These checks can help diagnose whether the clutch or pressure sensor is the source of the malfunction and aid in restoring proper AC function.

• Check the AC pressure switch and compressor clutch wiring
• Inspect the AC pressure sensor and clutch coil for continuity
• Ensure refrigerant levels are sufficient
• Verify all electrical connectors are secure

For detailed diagnosis and repair advice, chat with a verified mechanic on JustAnswer.com.