There's a strong spring attached to the rod that connects the two flaps.
This spring is located right where the small "arm" that's on the rod is
located, the arm the wire from the thermostat attaches to.  This spring
serves to hold the flaps in their "hot engine" (maximum cooling) position.
When the thermostat is cold, that is, when it's "collapsed", the wire from
the thermostat to the arm tugs *against* the pull of the spring, bringing
the flaps to their "cold engine" position.  As the thermostat expands with
engine heat the wire's tug is reduced and the spring on the arm pulls the
flaps back to their hot engine position.

The pull on the wire from the thermostat happens when the engine is cold,
not when it's hot.
---------------------------------------------------------------
Tom Young                       '81 Vanagon
Lafayette, CA 94549         '82 Westfalia
---------------------------------------------------------------
----- Original Message -----
From: "Jens Jakob Andersen" <jens.jakob.andersen@POST.DK>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, June 07, 2004 1:04 AM
Subject: Thermostat on aircooled - how dos it work?

Hi

I have tried to figure out how the thermostat on my aircooled 1982 2.0
Vanagon works.

I can see the thermostat housing, the cable, the pulley, and the flaps
regulating the cooling air.

I do understand that when the thermostat gets hot, it should expand.

But from looking at wiring and my engine when it is hot, I cannot see that
the wired gets pulled and that the "flaps" does open.

Can someone explain the full theory for me on the thermostat, the cable and
the "flaps"?

I know that I need to pull the thermostat, and test it - but still - I would
really like to get the idea of how this setup should function.

Happy driving

Jens Jakob