86 5KCS Self Check System

[Steve Sherman]

On my wife's 86 5KTQW an odd thing is happening with the self check
system, the one that flashes OK or the various symbols for faults.  Much
of the time (but not always) there is a combination of low gas and one
of the symbols with a triangle on together.  Both appear fainter than
normal. (and the gas is not low nor are there any other faults that I am
aware of to be reported)

Any guesses as to what this might be.  I plan on bulling the dash with
the light box for the warnings to look for crossed wires or whatever.
But I would appreciate if someone knows where the "brains" for this
system lies so that I can check that too.

TIA