Air conditioner not cooling entire rv

I am afraid that your air conditioner is not cooling anymore. Due you have checked it's compressor? What about the maintenance? You should have to consult an ac technician for the solution.

We had uneven cooling from our main A/C when we purchased ours. The bathroom and rear bedrooms would get enough to hang meat in. Our dealer sealed off the bedroom vent as the second A/C will cool this room. He then duct taped the inside of the bathroom vent so only a quarter of it was opened, this helped a lot. He also closed off the duct at the end vent in the living room, there was about two feet of duct there that was not needed. Fiver cools down great now. Hope this helps.

My TT has ducts that can be directed and a straight downflow that can be open or closed. Is it possible that your ducts in the main area are closed but the straight down flow is open meaning very little cool air is getting to the far rooms?

If the ducts are not obstructed they can be re-balanced to deliver similar air quantities in each location. There are many ways to do this by restricting the higher flowing outlets...

Ducted air is by far the worst at keeping a trailer cool. I've owned both and much prefer the direct flow from the air conditioner without ducting. The air flow from the ducted vents travel through the ducting in the roof which is warmed up by the heat and the air flow is not even close to one without ducting.

In a 35ft jayco I had, there was an option to disconnect the ceiling ducting to the front of the trailer, I made that change for a world of difference in keeping the front room cool in the fifth wheel.

On my current ducted air, opening the by-pass to the ducting works far better at cooling an already warm trailer even if it is directed downward.

You might have a disconnected or partially plugged vent. I'm not sure how you can check it though short of a plumbing camera. Maybe you can pull down or unscrew the vent cover in the toy hauler area and it might be obvious. If the vent is disconnected it will be cooling the attic and not the interior of the trailer.

Is the bedroom nicely cooled before closing the doors and the room warms up through the night or do you close the doors with the room warm and it never cools down.

I wonder if some debris , from construction of the TT, is in the ductwork or the ducts are not connected to the vents.

Maybe leave the doors open a bit and try a fan or two on the floor to move the cold air around.

B.O.

Normal for larger rv's to need dual ac units, that is why it is prewired. Just some people live in cold climates and don't need it so they make it an option.