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<02> Erratic Temp Gauge Cured

My '72 2002tii temperature gauge had become gradually more erratic
over the past few months.  Before, the needle would be steady at
mid-scale after the engine warmed up.  Recently, it typically stayed 
near or in the red range, and it fluctuated with certain electrical
loads (turn signal, headlights, a/c, heater fan, etc), going ever
higher with more things turned on.  These are the classic symptoms
of a bad ground connection and a fairly common problem in 2002s.

The troubleshooting and repair were easier than I imagined.  Using   
a digital multimeter, I measured the voltage drop between the 
battery negative post and the engine, then the drop between the 
battery and the chassis.  Both should be a few tenths of a volt at 
most, and this was the case with the engine.  For the chassis the
drop was almost one volt, and it increased to 1.6 volts with more
loads turned on.  While probing along the chassis leg of the 
battery ground cable, I saw that it had broken free of the battery 
terminal due to corrosion and wear.  This was the problem.  (The 
battery ground cable has a large wire for the engine and a smaller 
wire for the chassis.)  I temporarily attached the loose end to the 
battery, and the gauge got much better.  Then I installed a new 
cable, and now my temperature gauge is rock solid.  

The battery ground cable for all 2002s is part number 61-12-1-350-305,
and the book price is US$ 16.50.

Curt Ingraham
ingraham@domain.elided