BAD ! BAD ! SMELL FROM A/C

you probley have a rats nest in the duck vents ,have seen this plenty of times,the condensor has nothing to do with the smell,you could also have a leaking heater coil,it smells like antifreeze,and will blow out the vents.

It sounds like you have mold in the evaporator. The easiest solution is to find the a/c drain tube and spray some a/c cleaner up there. The cleaner should expand and dissolve the mold.

you also may want to take a look at your air filter and look in the vents around the firewall as they have said could be an animal or mold inside there somewhere or sitting water (condensation) from a while back. ive had that issue before and i replaced all the vents and connecting tubes and the air filter and it was fine. but also simple flushing it out with either a blast of air (cheetah air blaster) or taking all the parts off the find the source of the issue.