Larry:

Based on the last couple of years, here's my
recommendations:  With the fridge out, make
sure the intake/exhaust pipes are clean.  Think
of a flexible chain with a cloth ball at the end
that you pull through.  Check the place where the
air pump joins the air intake, too.  This with
the burner chamber detached from the tubes.  Check
the orifice and the burner compartment for
dust/grunge.  My fridge never goes out driving.
This includes the interstates and Syncro Safari
jeep roads.  If the exterior vent cover pieces are
not installed correctly, this will not be true!
Make sure the center plate fits down over the
end of the intake pipe cleanly.  For me it takes
one more finger than I have convenient to assemble
it!

I replaced my original fan with a Volterra fan
and thought it might not move enough air.  (This is
the current replacement to the Fridgemate.)  It did
cycle on and off.  I replaced it with two of the
3" Radio Shack 33 cfm fans mounted together on
a piece of angle alu.  Well, they kick on and
never turn off until the middle of the night.
[I tested them, so they are NOT running backwards.]
Meanwhile, the internal temp of the fridge goes up.
My thought is maybe since they are side-by-side,
they create some interference in the air path
and don't cool as well.  I'm going to remove
my fridge and put the Volterra back in.  If I
learn anything when I pull it and test again, I'll
post, but right now I am very suspicious of the
muffin fans--at least two together.  Perhaps a single
muffin fan is better than two.

On the original (noisy) fan and (I think) with the
Volterra, the internal temp stayed lower and,
certainly, the fan cycled on and off.  With the
muffin fans, they do not.

All this assumes proper propane pressure.  If in
doubt, check it via Mark Drillock's procedures posted
in the archives 2-3 years ago.  I had new regulators
installed locally and they test the pressure as part
of the installation.

Keep us informed of what you do and find.

                        Richard A Jones
                        Boulder, Colorado