You might check the four long screws that sandwich the top and bottom halves of the air conditioner together. They are suppose to be tight enough to depress the 14-Inch gasket between the roof and the air conditioner... You can see the gasket in this pictorial drawing...
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This ROOF GASKET will keep any water from the roof area from getting down into the trailer. If the water is coming from the air conditioner parts it may drip down inside the trailer.
When my air conditioner froze over it also dripped inside the trailer...
NOTE: After reading FPRESTO's comment I notice I forgot to say how much the roof gasket needs to be compressed. Mine is somewhere between 1/8-inch and 1/4-inch...
just my thoughts
Roy Ken