05 5.4. I've been following some recent posts and threads regarding intermittent AC issue here and some are close to my issue, but not quite, so instead of hijacking one of those threads, thought I'd start a new one. My issue that has happened a couple times in the last few weeks is that while sitting at a stop light, the AC will suddenly stop blowing cold air. Assuming the clutch is no longer spinning, but was not able to pull over to verify. This has happened 2 or 3 times in the past few weeks, each time while at a stop, idling in 80+ degree weather. If I turn everything off and turn it back on, all is good to go, sometimes for a couple of days. I checked the low side pressure and according to the range on my cheap gauge, I'm in the green with about 40 PSI, although I've seen it said that the number should be closer to 50 PSI. I saw the thread on the clutch gap and without actually measuring the gap, it looks pretty tiny. I don't have any feeler gauges at the moment. Will too big a gap cause intermittent operation, especially when the engine is hot or would that be a all or nothing situation? Anyhow, since this just started I know I have to probably gather more data, but I'm sure something is causing it. Any ideas are appreciated.

 

Check your air gap first. Even with a few thou of an inch can mean the difference in the clutch on hot days

 

An excessive gap might cause some slippage. My OE compressor had a wide gap (I forget the clearance) but the only problem it caused was a burnt relay because of amp draw trying to close the gap. It might be possible to close the gap with a shim and hub tool. I just ended up putting a new compressor on when I put a new engine in last fall, it was still working fine, I just wanted peace of mind with the OE compressor being almost 15 years old. I would definitely try to troubleshoot your fan clutch... The system is known for losing efficiency over time because the fan won’t pull enough air. It sounds like you’re good on freon but the only way to really know would be with a set of gauges to see what the high side is doing as well.

 

Stick with MEASURING the clutch gap first.