The duct work probably runs through an area that is hot and humid, i.e. attic space, and it isn't insulated.
is your fan running in the correct direction? are any of your ducts blocked?
from the air in the vent to the air in the room
The A/C extracts water from the air.
The air conditioner is low on refrigerant.
In order for water to flow down a pipe, there must be a vent to allow the air to escape. Above a toilet, on the roof, there is usually a pipe or a vent hood, which is connected to the drain pipe. When the toilet is flushed, the sound of water draining can be heard issuing from this vent. In addition to the above answer, the air rushing through the water may be the cause of the gurgling sound, which is the air escaping through the vent to prevent the build up of air pressure inside your water system.
the air coming from the vent is warm
Install an Automatic air vent
It's somewhat cold. It's just very little cold air coming out. Can't hear the vent blow the air as well.
you cant so do not turn it on or else your house will catch on fire
Install an automatic air vent on the line
The air from the vent should be 18 to 22 degrees F lower than the temperature of the air going into the return.
A rotten egg odor may indicate a dead rodent or animal in or near the ventilation system, whether in a house or car.