Posted by PL Brand on January 30, 1998 at 09:02:42:
In Reply to: ANOTHER WATER TEMP PROBLEM posted by Steve Ostroski on January 29, 1998 at 22:20:00:
When I first got my '51 M37, both the water temp
and oil pressure gauges were reading low, but the
motor ran fine, was quiet and no indication of
a mechanical problem. I found that on the water
temp gauge, the sending wire connection at the
back of the gauge was loose. The gauge still
moved a bit when the ignition was turned on -
it's still 24 volt - but the reading was low
when the engine was running. Cleaning up this
connection solved that problem.
Similarly, the OP would start out above 45, and
would run in that range 'til it suddenly would
drop to between 10-15psi at speed.
Found a bare spot in the sending unit wire about
6 inches back from the gauge that was occasionally
grounding to a brack, causing the gauge to read
funny. Taped up the wire, OP is now over 45 all
the time.
With electrica gauges of any kind, the sending
unit progressively grounds the current running
through the gauge, so any type of wiring problem,
short, etc. will cause the gauge to read strangely.
Hope this helps,
PB