In order of cheapness...
1. grounds
2. Broken Wire
3. Sending unit
4. Voltage Stabilizer(?)
5. Gauge itself.

Maybe I forgot something?  OH yeah... take it to the Dealer and grab
your ankles.

DM&FS

At 09:31 PM 8/18/2008, Budd Premack wrote:
>A friend of mine has a 90 GL with a non-functioning temperature
>gauge.  Is it likely that replacement of the gauge will resolve the
>issue?  Can the gauge from an 83 1/2 to 85 be substituted?  Could
>the problem be caused by the temperature sender, the connecting
>wires, or the printed dash circuit?
>
>Budd Premack
>91 GL, 86 Weekender
>Still the Land of Sky-Blue Waters