Mick, you said,

<<...12v seems kind of useless anyway if it doesn't work when you're not
running and shuts down when you stop and for twenty minutes after you
start up again.  What's the point?...>>

   No, the 12 volt heater doesn't shut down for 20 minutes after startup.
 If selected, it's on as soon as the engine starts up...it's just really
ineffectual, unless you make runs like I do...eight or more hours at a
time, stopping only for gas and to make and consume a quick sandwich...in
February.  Then it works ok...maybe sorta.  The rest of the year I use
propane when driving and 110 volts if available while camping.   Perhaps
the Dometic engineers thought a three-way fridge would be a good thing.
I don't.

   BTW,  when you run the fridge using 12 volt power, the heater runs
independently of the thermostat.  That is, it is always on, no matter
what the thermostat setting is.

        George
        '89 Westy, Wernher

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