The first thought it that the valve under the back seat must be on at least
about half all year round !
If it's kept closed, coolant just sits in there and contributes to the rear
heater core rotting out.
The least we can do is keep coolant circulating through it.
No heat comes out unless the fan is turned on of course.
So leave that valve at least half on, all the time, summer and winter. Or
full, but always 'some on' .
Your theory makes sense. 
Scott
www.turbovans.com 
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Jeff Lincoln
Sent: Monday, November 05, 2007 12:47 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Coolant Light

Ok folks - I think i already know the answer to this but I am hoping for any
further insight.

Driving back towards home this morning I noticed the collant light begin to
blink - needle stayed where it normally is just below the light. I was
concerned because it has never ever ever come on before (well in the approx
1yr I've had it running). Now I pulled over and shut down for a few. Checked
collant level all appears to be well. So I started her back up to see what
might happen and the light never returned. No signs of actual over heating.

So my though is this. I opened the valve (if that's the proper term) to the
rear heater on Halloween night. I ran the blower breifly that night but not
since. THen this morning it was cold and I had the hound in the back so I
turned that rear heater on full blast for him. I am thinking that since the
valve was closed off and I really haven't used that heater much maybe there
was some air hiding in there some where and I just need to bleed the system.

What are your thoughts?

--
Thanks,

Jeff
'90 Carat (Grover)
'86 (We call this one Parts)
'85 GL (Preparing to move to a new Home)
'78 Bus (Melissa) Patty's Bus