Go into the engine compartment, with the key in the 'run' position and
ground (temporarily) the wire to the sending unit on the back side of
the left head.  The gauge should go to full hot.  As soon as it does,
pull it off the ground to not damage the gauge itself.

If nothing happens, check to make sure you have power to the gauge
itself.  If you do, I would suspect a bad gauge.   

If the gauge checks good, replace the sending unit that screws into
the back of the head

Sep 2003
------------------------------

With the ignition switch ON, ground the wire that goes to the heat
sending unit in the head, ...briefly.

The gage should go right to "HOT". If it does, the dash unit is OK,
and likewise the wiring.

If there is no response, then it could be one of 3 possibilities:

a) the wire from the sending unit to the gage is open somewhere

b) there is no power to the "ign" stud on the back of the gage

c) the gage itself is bad

With a test light and a clip lead or two you can check for a & b. If
neither of them apply, then it's probably a bad gage.

Sep 2003
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