Main vent fan in center of coach

[Pete Masterson]

My coach has a Fantastic Fan in the bathroom ... that works as
expected. It also has a vent fan located more or less above the
kitchen area in the forward section of the coach. This roof top vent
fan is controlled by the thermostat (when set to "cool") that also
controls the electric Perfectoe heater in the toe kick area under the
kitchen cabinets.

Through experimentation, I discovered that you set the thermostat to
"cool" and move the temperature setting toward the lower temperatures
to get the fan to cycle on. I also find that I can simply set the
"fan" switch from "auto" to "on" to get the fan to run. I can set
both switches -- heat/off/cool to cool (with the temperature setting
below the ambient temperature) and "auto/on" to on and the fan will run.

Now the question: No matter how the thermostat is set, the fan will
sometimes come on immediately when the switch is set appropriately
and sometimes will come on after a delay of some period of time (from
a few seconds to a few minutes). While the fan is running, sometimes
it will run continuously for a long period of time (that is, until I
turn it off) and sometimes it will shut down for 5 or 10 seconds ...
or a minute or two ... and start up again. During this start/stop/
start cycle, I've observed the thermostat with the cover off and
noted that the thermocouple in the thermostat does not 'flip' -- so
the on-off-on cycle _is_ _NOT_ being affected by the thermostat.

It is possible that there is a faulty circuit breaker that shuts off
power and then resets.

So, does anyone have any ideas about what is causing this behavior?
And, does anyone know where the circuit breaker that protects this
circuit might be hiding? (I presume that the fan operates on 12 volts
-- I haven't, yet, disassembled anything to start testing voltages,
etc.)

Any details or comments will be appreciated.

I'm thinking of simply replacing this fan with a Fantastic Fan (to
get the skylight effect as I have in the bathroom), so has anyone
done that? And, is it a good idea?

Pete Masterson
'95 Blue Bird Wanderlodge WBDA 42
aeonix1@...
On the road at