Several years ago, had a unit that did the same thing. Turned out that box under the dash where the chilled air came off the AC coil, was in direct contact with the humid air inside the coach. So what to do...went to auto upholstery shop, purchased a small quantity of that heavy cotton batting they use for sound deadening, some spray adhesive. After a bit of custom cutting, fitting, gluing...the project was deemed a success. NO MORE DRIPS!
Since the water dripping was ice cold, and falling in DW's feet, and, was now not, we instantly became happy campers!
Back to a 5'er after 4 yrs fulltime.
Pulling with a '14 2500 ram, 6.4 Hemi.
Montana High Country 31RE