temp gage calibration?

[Luke Rickert]

The coolant temp gage on my 87 4kq reads high. At least I hope it reads
high, during normal operation the fan cycles as expected and an inferred
thermometer says that everything is at around 190 F, but the gage goes
right up to the top or second from the top line (~240 F ). The needle
drops a bit on the highway, but it doesn't leave much room if there is
actually something wrong and the temperature needs to get higher. Has
anyone successfully adjusted the little sliders things that are
accessible through the back of the gage?  It appears to be adjustable,
but I haven't had much luck trying to simulate the resistance, current
and voltage conditions to calibrate the max and min levels. (it started
smoking which a good indication that my guesses about the mystery units
in the manual were incorrect)

I think this problem stated when I installed this instrument cluster,
the old gage didn't read nearly so high. Also all three of the temp
sensors (both of the ones in the upper coolant flange and the fan
control sensor in the bottom of the radiator) have been replaced in the
last year, so I don't think the problem is with the sensors. I am fairly
certain that it is the gage, although I suppose there could be some
other cooling system malady actually making the system actually run hot.
a bad thermostat? The coolant and water pump were changed last summer
when I did the timing belt.   

thanks

Luke 


-- 
Luke Rickert
www.engr.orst.edu/~rickert