I think it mainly senses temp in the vacinity of the fins, and direct
contact is not essential.
For testing, I just aim a hot air gun or hair dryer at  it and see if it
turns on the fan.- and if it's working, it'll turn on the fan in a minute
that way.
I've had the fan come on just from the van sitting in the sun on a very hot
day too.
----- Original Message -----
From: "neil N" <musomuso@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, July 14, 2008 11:49 AM
Subject: Re: Dometic Thermistor Function?

> ah ok.
>
> The one on the back exterior.
>
> When the fins reach a certain temp, the switch inside (bimetalic strip
> I assume) closes and the rear fan comes on.
>
> You might be able to "adjust" the piece of metal that screws to the
> fins, to help it contact the fin. You can also put a small dab of
> thermal paste between fin and this sensor.
>
> I did the above to mine, and it turns the fan on just fine.
>
> Neil.
>
> On Mon, Jul 14, 2008 at 11:30 AM, Michael Diehr <md03@xochi.com> wrote:
>> Perhaps I used the wrong term?  I'm talking about the electrical
>> gizmo, about the size of a 4 quarters stacked together, that the
>> yellow wire connects to (the yellow wire powers the rear fan on/off).
>> It's mounted on my dometic to the top set of fins on the back of the
>> unit. It's a bit loose, and I'm wondering if it's important that it
>> have a thermal contact with the fin, or if it just measures ambient
>> air temp?
>>
>> On Jul 14, 2008, at 8:49 AM, Roger Sisler wrote:
>>
>>> That probe needs to be tight against the rear of the aluminum
>>> evaporator.
>>> Metal to metal contact. There is a channel along the entire length
>>> of the
>>> evaporator's rear that the probe sticks into. A plastic cord about
>>> 1/8 inch
>>> in diameter and 4 inches long presses in on top of it to keep it in
>>> place.
>>> That white cord should still be around. It is probably still in the
>>> groove
>>> and the probe just slipped out.
>>>
>>> It measures the temp of the aluminum plate.
>>
>
>
>
> --
> Neil Nicholson '81 JettaWesty "Jaco
> http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
> http://web.mac.com/tubaneil
> http://tubaneil.googlepages.com/