If the compressor kicks in, over much time (days) it is most likely there is no leak in the system. The system must have a minimum charge to allow the compressor to kick in. If the charge drops below a certain level on the low side the computer prevents the compressor from kicking in. That said, first thing I would do is see if there is sufficient charge in the system. It might be on the low side where it allows the compressor to kick in but is not high enough to sufficiently charge the system. I think (Best to check as I am not sure) but with the compressor running the low side should be about 35 psi and the high side about 150 psi. Again, check these out as I am not sure at this time about those values. If the pressures are within specs and the interior fan works in all threes positions, I would look to see if the flap valve is working. If it is stuck in the heat position the interior air after it is cooled by the AC unit is run over the heater core and this will warm it up again. Somewhere on this forum is a good diagram on how the heater box works and it will clear this up. Replacing the condenser is not as easy as it seems as the front clam needs to be removed and the radiator removed opening up the engine antifreeze cooling system. Let me know.;.
"It always seems to be something!"