AC diagnostics for 2007 Toyota Corolla S

[bonzovt]

I've been having AC issues for a few weeks and already tried some things, but still can't get to the root of the issue. Doesn't help much that it will be 102 degrees today! Maybe someone has an idea??

Out of nowhere, AC stopped working one day. It was just blowing warm air and the compressor clutch was never engaging when I turned on AC. Tried getting a recharge but of course it didn't work. They told me I needed a new compressor. I brought the car to some friends to diag the issue and they made a quick cable and hooked it from the car battery directly to the compressor and AC starting blowing cold air! They said it was electrical, probably my relay. I went and got a new relay the next day and put it in myself, turned on the AC and the compressor clutch would start turning, then stop, over and over again. My friends said it had something to do with the pressure at that point.

I brought it back to the shop and had them look and possibly recharge to normal levels. They said it was a bad pressure sensor. I got one from the Toyota dealer and had the shop put it in. Then they recharged and gave me the car back saying I had AC, but the compressor was still bad. They said the pressure levels were off and it was because the compressor wasn't working properly even though I had AC. They said it could work for 5 days or 5 months but would eventually give out.

Took the car back to my friends to look at pressure levels and they were definitely off. A buddy who does AC took the car and flushed the system and filled it up with 134a and made sure it had the correct pressure levels. After then it worked GREAT for about a week and a half. Went on an 8hr road trip 4th of July weekend and worked the whole way up and driving around the city. The car sat for a couple days and then on the way home, no AC! Could never get the clutch to kick on. Somehow, after 4hrs on the road I was running the defogger pretty high and noticed it was getting cold. Turned on AC and it worked for about 20 min, then went away. I could "trick" it on like this the rest of the way home, but since then I just have no AC at all.

I'm still wondering if this just means I should replace the compressor. We just seem unsure, because when we get the clutch to actually kick in, the AC works great. Could it just be that since the compressor clutch is flaky, then the compressor really is the culprit? I bought a newer Corolla to avoid having random car issues like this, but I guess it is unavoidable! Is it still possible there is some smaller part going bad? Any ideas/thoughts would be much appreciated!!