[jcurtis934]

Could be lots of things. If you only have zone 1 on and turn the thermostat down to a very low number with the fan speed set to auto, can you hear the compressor kick in at all? If you can but only warm air comes out, then it's probably not something you can fix. It may not have worked when you bought it if you ran both ac's at the same time since they share a common duct system. You can remove the cover on the ac on top of the roof and make sure the condenser is not clogged with crap. Easy to tell if the only clean spot is a small circle where the blower fan directs most of its flow. If this is the case, the ac will blow warm air. Be gentle in cleaning it. I use a shop vac to suck the inside surface clean, then reverse the hose to blow air out the hose to blow out the fine dust that clogs up inside the fins.