Water will always travel the path of least resistance.
It may very well be condensation and no real concern, but it could also be a leak that needs to be addressed. If water is coming from the AC air handler you have a problem that needs to be looked at ASAP. Now while there is water there; remove the plastic air handler cover. Feel the edges of the exposed top plywood to see if it is wet.
When it happened to me, water poured out of the air handler plastic cover. (it had pooled in the hollows) Turned out the factory had not properly installed the AC unit (not torqued enough on one side and over torqued on the other) and water had finally worked its way under the foam roof seal. Once it had a path dirt will prevent the foam seal from resealing. It will leak forever until the AC is removed and the foam seal replaced. Follow the installation instructions carefully if you do it.
My Coleman Mach II has yellow torque tabs that indicate when the unit is evenly tight all around the hole. The foam seal must not be over tightened to collapse the seal. It need to be tight enough to weather proof but not so tight that vibrations beat the roof like a drum.
http://www.forestriverforums.com/for...leak-9985.html
http://www.forestriverforums.com/for...g-on-7112.html