Does the AC give you problems when at higher than 2000 rpm or 55+ mph or accelerating? Does the ac cool properly? Does it sound like it's working too hard, not turning right, maybe even starting to smell burnt? That would indicate a seizing ac clutch, but not likely your problem. I'm wondering out loud about the ac switches that feedback to the pcm somehow causing your problem, but I can't quite make the clear connection. If your ac isn't working, I'm wondering if your ac clutch field coil would be the problem by not telling the PCM it's on. I'm not sure. Hopefully, Rod will respond.