Date:         14 Nov 1995 08:48:04 -0800
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         "Harvey Chao" <Harvey_Chao@smtp.svl.trw.com>
Subject:      Re: Coolant Temp Indication

                      RE>>Coolant Temp Indications                 11/14/95


>From: GDURSTEW@oimb.uoregon.edu
    hi Jim and Drew !
 i don't doubt what you said Drew, but i've had the same gauge problem in my
rabbit and i'm sure mine is completely electrical (i.e., NO overheating)
because at the same time the temp gauge shows hot the fuel gauge goes up as
well. never thought it serious enough to fix it, figured it's mebbe a loose
ground connection in the instrument panel ???
   

=============
When you mentioned a similar problem in your rabbit, the "memory light" went
on.  I seem to recall that VW uses a voltage regulator for the dashboard
instruments to stabilize the voltage for the instrument cluster independent of
battery voltage (within certain limitations).  Check you Bentley circuit
diagrams to be sure.  Both the temp and fuel gauges are simple circuits that
measure and display a current flow that is a function of supplied (regulated)
voltage and a variable resistor (in the tank via a float, or via a temperature
variable resistor (varistor) in the water jacket).  The voltage regulator is
the common item in both gauge circuits.  Check it for intermittant operation
or a bad connection.
Harvey