Jon,

You're not alone. I've had my gas cap and door locks freeze up twice. Each
time it happened the temperature had dropped down to the low teens. Since I
was overnighting inside the camper I could unlock my doors in the morning to
exit the vehicle. My temporary solution was to hold the gas cap key with
pliers and heat it over a range top burner, and then quickly inserted it
into the lock. The heat transfer melted the frozen water inside the lock.
Since I didn't want to overheat the key too much I had do it a couple of
times until it worked.

Deciding I didn't want this hassle any longer I queried my camping friends
and the consensus was to use a lock de-icer. Upon my return home I bought a
small can of Qualco brand pressurized "Lock DE-Icer" at my local Pep Boys.
Use it, or a similar product, as a preventative and carry it for emergency
re-applications. BTW, after the first lock-up I did spray some WD-40 in my
locks. That made for easier key action but it sure didn't prevent the locks
from freezing.

While we're on the subject I should mention I also had my parking brakes
lock up on those two occasions. Each morning when I released the hand brake
its' cable disengaged at the rear underside "Y" junction. After searching
Deja.com I found this was a problem with many vehicles, not just Vanagons.
The only cure when camping I can think of is to remember NOT to apply my
parking brake whenever I expect overnight low temperatures. Also I think
it's also more likely to happen when the underside has been soaked with
water after driving through rain or snow. I suspect I could remedy the
problem by performing R&R on the mechanical brake cables and their drum
counterparts but I don't want to go to all the trouble.

Garrett Adams
83.5 Adventurewagen GL
Stockton, California