Looks like condensation building up on the glides and getting splashed on the wall when opened/closed to me. Is there any vapor barrier to kill the air flow around the cabs? Insulation isn't going to stop air flow and moisture from coming in and condensating on the metal. Can the units d be pulled out and put back with vapor barrier around/in the opening?
To a small child, the perfect granddad is unafraid of big dogs and fierce storms but absolutely terrified of the word “boo.” – Robert Brault