If the gauge is working, I think this sounds like the sensor.  Had
the very same thing happen to me in an A2 Jetta, which I would assume
shares a lot of the same instrumentation.  In my experience those
sensors (both for the gauge and the ECU) are only good for a few
years.  Luckily they're pretty inexpensive; I recommend keeping
spares on hand.

Allan

On Nov 28, 2007, at 11:43 PM, Scott Daniel - Shazam wrote:

> First you need to find out if it's really running that cold, or if
> the gauge
> is just reading low or not working.
> You did say the heater works well - so maybe it is running warmly
> enough.
> Easiest way to find out temps very quickly and completely non-
> intrusively is
> with an infrared temp gun - so many uses you gotta have one.
> Check the main hoses coming off the engine, you'd like to see 180
> - 190 or
> so warmed up .
> If I am wondering if the temp gage is working, I just jumper the
> two wires
> together -  undo them from the *gauge* sensor, not the ECU one,
> jumper them
> together, turn on the key, and see if the temp gauge pegs.    If it
> does,
> it's workin.'
> Scott
> turbovans
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
> Behalf Of
> David M
> Sent: Wednesday, November 28, 2007 8:15 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Changed thermostat - temp gauge still reads stone cold
>
> I went on the first extended test drive today after
> replacing my thermostat. The temperature gauge still
> does not move above the lowest thick bar. If anything,
> it's worse than it was before. Is it possible the
> replacement thermostat was bad (it was a brand new
> Behr)? Or, is it possible there is some other problem?
> The van drives well and puts out lots of heat from the
> vents. The fan is not running. I hate to think I'm
> damaging the engine.
>
> David ('87 Wolfsburg 2.1 auto)
>
>
>
> ______________________________________________________________________
> ______
> ________
> Never miss a thing.  Make Yahoo your home page.
> http://www.yahoo.com/r/hs
>