First thing I check is how the batteries are. If you have a motorized step, is it opening at its normal speed? If it's very slow...or not moving at all...if it's not frozen or rusted/corroded, the likely culprit is the batteries (especially if you didn't have a maintenance charger or shore power plugged in.) If you have a battery disconnect switch, turn it on. Did your coach turn on normally? If so...great! If not...well, check the batteries for voltage. Should be more than 12 Volts...If it's on a multistage charger, then they should be happily kept at around 13.x Volts.
water intrusion. Especially the roof. Run your hand around all vents, the A/C unit, any skylights you have, your windows and the exhausts/chimneys for various appliances and your stove vent fan. Often these are in the cabinets. Open them! Feel the roof INSIDE the cabinets too. If it's damp, try and find out why. Leaving things damp all storage season will do more damage.
I also check for anything I DIDN'T really use over the last season. Removing those things will give me more efficient use of space (and let me store more stuff!)
flashlight! Check your fridge for mold/mildew. Even a well-cleaned open fridge can develop some. Believe me...I HATE cleaning that nastiness!! It pays to look now, when a simple spritz with cleaner and wipe will fix the problem!
A problem avoided is a good thing!
I also take this time to check the water in my batteries. Since I leave them on a 4-stage maintenance charger, I like to make sure they have the proper amount of water and/or the charger is functioning properly (not boiling them to death). Batteries are expensive -- If maintained properly they will last for many years. I also lift up the edges of the cover to check underneath. Not for anything specific, but just general condition. Especially up by the engine bay. Is there anything leaking? Puddles under the Engine or Transmission could be a bad sign. Catch that sort of thing early and you're in better shape.
This may sound a bit crazy, but when I'm done I just sit on the couch for a while and look around. I mean, I miss my RV and traveling. Think of it as a visit. You can talk to it if you wish. That's OK...unless it answers back. Then seek professional help. Really. And HAPPY NEW YEAR!
Be Seeing You, Down The Road...
Rich "The Wanderman"