My trailer has never leaked before.  I've had it for about 2 years.  I was gone the last several days (without my trailer).  We received about 5 inches of rain, and heavy winds.  I did not return home to my trailer for several days after the rain.  I noticed the edge of my matress being a little damp.  I can find no signs of where the leak came from, other than it is just about under the edge of my AC unit.  There are no water spots on the ceiling, on the floor, or the walls.

My question is, can an AC unit leak through the air flow portion if a hard rain hits it just right?  Or is it wishfull thinking on my part.?  I thought maybe if the rain forced its way hard through the back coils, it could maybe pass down through the air duct?  My trailer was not sitting level at the time, and the dampness was toward the downhill side.  I have hit all parts of the outside roof of the trailer with a hose since, and cannot find a leak.  My trailer is stored outside, and never leaked before.  I can't find a leak in the seal between the AC and the roof.  My roof is a one piece aluminum, with the only seam being on the outside edge.  I sprayed the hose on the caulk line and cannot make it leak.

Any input would be helpful.

Thanks

Sometimes on a newer installation, the hold down bolts will loosen as the AC sets down onto the roof with the traveling vibration. If you had a heavy wind, it's possible it could have driven the rain under a loose seal.

You can pull the inner shroud, loosen the bolts and partially lift the AC unit to inspect the seal to roof surfaces for any debris. A sealant could be installed, but it usually isn't necessary. Make sure the seal isn't rolled and remains flat, set the unit back down and re torque the bolts. It may be all that is required to stop the leak if that is your source.