Turn the engine off and check the fanbelt. If its shiny where it fits in the pulley grooves,  that is a sign its slipping. You can also put your thumb on it between pulleys and see if it moves much. Half an inch of deflection is about the limit.

The tension can be adjusted pretty easily, but if the belt is shiny or looks funky I'd go ahead and replace it. If you break a fanbelt and the redlight stays on its critical that you shut the engine down before it overheats (that is why it is called a fanbelt).

Good luck!

--- On Fri, 5/30/08, Donna Skarloken <dskarloken@GMAIL.COM> wrote:

> From: Donna Skarloken <dskarloken@GMAIL.COM>
> Subject: VW 1973 Thing LVC (Happy Friday)
> To: vanagon@GERRY.VANAGON.COM
> Date: Friday, May 30, 2008, 4:37 PM
> My vanagon content is that we drove our Syncro to Bugorama
> in Sacrament last
> Sunday; it was a nice time with decent weather (meaning
> cooler instead of
> boiling hot like it usually is).
>
> My parents' Thing has mostly been sitting for years.
> We start it and drive
> it a bit but not much.  My mom is still with us but cannot
> drive so Sunday I
> drove her around in it for a bit.  Everything is fine but I
> noticed a couple
> of times when coming down from speed (i.e. like off a
> freeway offramp) the
> generator light would come on but then go out.  Seemed odd
> to me.
>
> I plan to drive her in the Thing to the Norcal picnic on
> Sunday in Stockton
> for her birthday but I am a little concerned about that
> light.  Any
> suggestions?  Is it probably just age?
>
> It has a brand new battery.  I believe it has a generator
> and not an
> alternator but I am not a Thing expert (I think the
> printiing by the red
> light says "gen").
>
> Thanks for any suggestions and also if anyone knows of a
> Thing list please
> let me know so I don't bug the Vanagon list about this
> stuff!  Thanks again.
>
> Donna, 87 Syncro