Air Conditioning issues

I just took a trip in my 2003 Dakota 4.7 V8. It reached over 90 degrees a couple of days so needed the air on. I discovered water on the floor of the passenger side. I reached up under the dash and the black box was wet like it was sweating. This was slowly leaking on the floor and under the mat.

Any idea what is happening? The air is blowing good and cold but seems to be medium cold and then real cold on a 4 hour trip.

HELP!!

Clean out the evaporator drain hose. When the AC is working, humidity condenses on the evaporator coil and drips/runs down to the bottom of the evaporator housing. There is a small rubber hose that routes the water out of the housing and onto the ground. If the hose is plugged up, water accumulates in the housing and overflows onto the floor. From under the vehicle: locate the evaporator housing and you'll see the drain hose, clean it out and you should be good to go. Do not poke metal objects in the hose, it can puncture the evaporator.