Moco AC failure

That sounds awfully familiar! I had a similar issue with my old BMW 3 Series, although the cause might be different. The symptoms were identical: AC stopped working, no cold air, and the compressor wouldn't kick on. In my case, it turned out to be a faulty pressure switch. The system thought there was a refrigerant leak, so it shut everything down to prevent damage. It's a safety mechanism. Have you checked your refrigerant levels or looked for any signs of a leak?

Interesting about the pressure switch! How did you diagnose that? And if the refrigerant was low, wouldn't there be other signs, like hissing or weird AC noises before it completely died? I haven't noticed any unusual sounds, just complete failure. Also, how did you pinpoint the pressure switch as the culprit and not something else?

I used an AC manifold gauge set to check the pressures on both the high and low sides. If the pressure is too low, the pressure switch will prevent the compressor from engaging. The diagnostic process involved bypassing the pressure switch (which I do NOT recommend unless you know what you're doing, as it can damage the compressor). Since it started working when bypassed, I knew the switch was the issue. Honestly, given your symptoms and the potential cost you mentioned, I'd strongly suggest taking it to a reputable AC specialist. They have the equipment to accurately diagnose refrigerant leaks and test the functionality of all the components, including the compressor, expansion valve, and pressure switches. It's worth the diagnostic fee to avoid throwing parts at the problem and potentially causing more damage. You can ask them to do AC diagnostics and give you a breakdown of costs.

Thanks a lot for the advice! I was trying to avoid a mechanic, but it sounds like I'm in over my head. I'll take it to a specialist and have them check the pressure switch and look for any refrigerant leaks. Hopefully, it's something simple. Really appreciate the help!