Mossy Cat, I haven't winterized one of these before, sorry I can't tell you the exact location. Usually you can hear it running so it might help you narrow down an approximate location. Some common places in trailers are the vented area under the sink or stovetop, inside the front storage compartment behind a "false" panel, (you will most likely need to remove a couple of screws holding the false panel on) next to or under the bed (in some cases you just lift the bed which may or may not be on gas assisted struts).
94-Newmar Kountry Star 40-KSDP
Spartan/Cummins 8.3C-300HP/Allison 3060 WTEC-II/25yr RV Tech RVIA Certified/Onan-Cummins Certified