Yesterday coming across Mississippi I had the front roof air conditioner on with the fan on "high" and the dash fan helping to circulate the cool air, works well (and thanks to a member here). Condensation started flowing from the closed outflow vents on the ceiling unit. I know I have seen the cause of this somewhere but am unable to locate it in the archives here or in the manuals for this Dometic unit. What do I need to do?
Horace,
Could be dirty cooling fins on the unit and/or a clogged drain. Take off the AC shroud and remove the screws that hold the sheet metal over the inner works to get to both sides of the fins. A vacuum cleaner and/or air hose is real useful for this situation.
One last thing that I learned from Gary O. Be sure the temperature sensor probe is inserted into the fins -- lower rather than higher.
I had that issue on my 01 so I replaced two of the AC units. THe pan was rusted thru on the bottom. That allowed it to leak thru. Sure check the other stuff but the new units do not leak at all no matter the temps or what I run the fan speed at. THe third AC will still leak a bit but I decided not to replace that one as I do not run it very often.
As I found out and posted recently: check and tighten, if necessary, the four bolts that hold down the A/C on the roof. It is entirely possible the gasket uptop is not compressed sufficiently or is incapable of further compression so it is letting water pass. You have to remove the access panel on the inside in order to access the bolts--one in each corner.
Nitehawk
Horace, like you, I have a 2003, 320. Actually our coach was a couple ahead of yours - we are 6182, so I am sure the air-conditioners are probably the same. I have experienced waterfall events, and I attribute it to a combination of influences that I don't think can be corrected. The last time this happened, I had the fan on high in 98 degree ambient high-humidity. The center unit started dropping water through the exhaust grill. I went up on the roof, removed the plastic cover, and then removed the sealed sheet metal cover and found water in a water-tight depression high enough to overflow directly in front of the evaporator core. There was no icing issue, and the drains were perfectly clear. Apparently what happens, due to a poor design, is that the tray that drains the evaporator is just slightly larger than the evaporator footprint. With the blower on high, and the climatic conditions right (high heat and humidity), water droplets are pulled off the evaporator into an area where they cannot be drained except inside our coaches. I have never camped in the heat of the summer in the desert, but have been in Missouri in 105 degrees, and have never found the need to use the high blower speed in a.c. mode. Maybe I missed something, but this appears to be the case.
Gregory S
2003 Designer