HOT Temp. Guage

[jdouglas@mitre.org (jason douglas)]

Hi -

The temperature guage on my '86 5000S is definitely goofy at the moment.
After about a mile of driving, it showed the temperature as being somewhere
near meltdown - two or three marks from the top of the scale.  The engine
wasn't that hot - the heat was only tepid.  This morning, with a stone cold
engine it showed about two marks left of the middle marker.

The archives show that the standard failure mode is either a dead guage or a
gauge that reads full hot all the time.  I found no mention of any problems
in between.

My first step this evening will be to clean the contacts on the sensor. Next
would be the voltage regulator in the instrument cluster.  However, the
needle is quite steady and the fuel guage reads correctly.  What are the
chances the problem  is the regulator, and what are the chances that the
problem is the temperature sensor that runs the guage? 

BTW, I just replaced the radiator thermo-fan switch, perhaps needlessly as a
result of a faulty temperature guage reading?  :-(

Jason Douglas
86 5000S