There should be a fused constant (B+) voltage at one of the fan wires. The
fan thermal switch is on this + feed. With a VOM - probe to vehicle frame
and + probe to appropriate wire at vehicle side fridge connector, you
should see battery voltage.
And yes, the thermocouple is the switch that completes the circuit.
There should also be a wiring diagram on the fridge.

Since you're doing mods, if you don't use the city water connection,
would recommend putting in an exhaust fan there. I wired mine so it runs
off switched power from the aux battery.

Neil.

On Sat, May 30, 2015 at 9:07 AM, Mike South <msouth@gmail.com> wrote:

>
>
> The last thing I want to do before putting it back in is to hook up an
> external and internal fan.
>
>
>
> ... One wire (I think the
> yellow one) goes to a thermocouple that completes the circuit (and
> turns the fan on) when the heat-dissipating fins on the back of the fridge
> warm
> up.
>
> However, under AC power, I'm not detecting a voltage on either the blue or
> the yellow wire.
>
> If I'm understanding how the fan works, one of those wires should be
> constantly at 12v.
>

--
Neil n

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