Manually remove any large pieces of dust, lent, etc., then add about a half cup of bleach to it, let it set 12-24 hours then flush it with water, or turn ac back on.
Inside the unit under the evaporator coil. The condensate drain line is attached to it.
how to check out the relay in a central air conditioning unit
Make sure the unit is slightly tilted back in the window so it can drain, if the unit is still leaking you may need to remove the unit and cover to clean out the drain it may have a blocked drain.
re-level the unit,and/or clean the coil
The drain line for the condenser unit it is located near the firewall on the passenger side of the vehicle, near the floor panel.
Change the filter and clean the coil. If it smells like a dead animal clean your duct work.
You do not need to pump the system down just to clean the coil unless you are planning to remove the coil completely from the unit.
If the drain line from the ac unit is tied into the sink drain line, the trap leaving the ac unit has probably run dry. Fill the trap at the ac unit with a cup of water and it should stop the noise. Assuming a proper install, kinda hard guessing about it from here without seeing it.
Water will condense in the inside unit of the air conditioner. This is because the coils in the unit get cold (ad expected) and moisture in the air condenses on them like moisture on a cold glass. There should be a drain inside the unit to drain this water. Check that it isn't clogged.
You will need to unhook the dirt receptacle at the bottom base of the unit. Then, empty the debris into the garbage and replace the receptacle.
Central Unit ended in 2011.
Central processioning unit.