At 21:45 10/4/99 , you wrote:
>I haven't figured out how that circuit works yet, but it's on the list
>of things to do.

Tom, according to the 83-4 schematic, the low-coolant alarm circuit, when
activated by too high a resistance across the coolant sensor pins, simply
pulls the gauge input to ground, simulating a very high temp.  At least on
these, any legitimate flashing of the light will be accompanied by an
overtemp indication on the gauge, whether caused by the temp sensor or the
low-coolant sensor. *Any* flashing of the LED with normal temp indication
is an internal gauge failure.  The gauge itself has three inputs: +10v,
ground, and the connection to the variable sender resistance, so the
decision to flash the light has to be internal to the gauge.  And I just
now took the gauge originally from the '84, which flashes long and hard in
damp weather, and hooked it up to power (no sender).  It flashed perfectly
normally on multiple tries -- until I breathed into the gauge, at which
point it started flashing and continued indefinitely.  Case closed, I would
say.

Now I've had a report that on at least one later-model van, disconnecting
the level-sender plug resulted in flashing light but no overtemp
indication.  Looking at the schematic I don't see how this could be, but
there it is.

david

David Beierl - Providence, RI
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"