I have a similar situation with the exception that some time ago I bought a used blower for $45 and replaced the non-working one.

As for the A/C, it will cool for a bit and then just blow warm air. This happens in warmer (80ish +) weather. The system is sufficiently charged and when it is on it cools quite well. I had read a while back about some sensors that could possibly be malfunctioning but have not been able to find that information again. It seems to me that is was some sort of a temperature sensor located somewhere around the compressor ( I hope that is sufficiently vague). The sensor located near the low pressure service port seems to be staying closed which seems to be what it is supposed to do. If I unplug the harness from it the compressor shuts off. I am going to check for a bad connection there tonight but I don't think that is it since the A/C works fine when the weather isn't so hot.

If anyone could help or direct me to some detailed A/C systems information I would be most appreciative.