Ford Explorer P0352 Code: Ignition Coil A Fault and AC Blowing Hot Air Diagnosis
My 2004 Ford Explorer V8 is showing fault code P0352, indicating a primary or secondary circuit malfunction in the ignition coil A (V8 engine). I have already replaced all spark plugs, spark plug boots, and all injectors. The crankcase sensor has also been replaced. The vehicle now exhibits a rough idle and runs at an unusually low RPM of around 500–600. Despite these replacements, the P0352 code persists. Additionally, my air conditioning system is blowing hot air. I've noticed that the AC clutch is not engaging or cycling on and off. When I directly connect a battery positive to the AC clutch relay in the fuse panel, I hear the clutch activate — but it does not cycle properly. There are no visible leaks in the refrigerant system. What could be causing both of these issues? Is there a connection between the ignition coil fault and the AC problem?
P0352 relates to the ignition system, specifically in a Coil-On-Plug (COP) configuration with eight individual coils. First, inspect the connector on the #2 coil for looseness, corrosion, or damaged wiring and pins. If the issue persists, try swapping the #2 coil with another cylinder's coil to determine if the code follows — this helps identify whether the problem lies in the coil itself. Regarding the AC issue: I do not recommend bypassing the system by directly connecting battery power to the clutch for extended periods — only perform a brief test. Ensure there are no other diagnostic codes present. The key is checking both high and low refrigerant pressure. Low static pressure can prevent proper operation of the compressor, leading to hot air output even if the clutch engages.