Tom,
The refer has a water ammonia mix sealed in the evaporator tubes,
some people have removed the refers after setting and rotate them
over and over to help mix the solution back up, the constant movement
from driving does this also. Its a sealed unit so no service can be
done to remove air or refill ect. The unit needs to be level when
parked because the solution collects at the bottom where the burner
(on gas) or the heating element (on electric) boils the solution and
turns it to gas where it circulates through the system and cools the
refer by means of evaporation, then goes back to liquid returns to
the bottom to do it all over again. They made 2 way and 3 way refers,
2 way work on gas and 110volt, 3 way are gas, 110volt, and 12volt,
which won't cool on 12v only used to help maintain the temp while
driving. The refer should have some means of switching from 12v,
110v, gas, either inside the refer or inside the access cover outside
with a seperate thermostat for either gas or electric. If not level
when parked the solution won't collect under the burner and it will
eventually ruin the unit. Hope this helps you some.
