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<DIV><FONT size=2>The fact that one has been intermittent for a while and the
other only happened recently implies they are not the same fault.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>The voltage stabiliser only supplies power to the fuel and
electric temp gauges, not the tach. The confusion with the tach is that
the green supply to the tach is often daisy chained off the 12v terminal feeding
the voltage stabiliser. If all three were failing to register then it
could be the green supply to the voltage stabiliser (and hence the tach)
that had failed, other than that they are separate problems.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Because the fuel and electric temp gauges are fed from the
voltage stabiliser if the stabiliser fails in that it continually supplies
system voltage to those gauges then they will read high, and will vary as system
voltage goes up and down. The simple test for that is to switch on the
ignition but don't start the engine, and note the fuel gauge reading once it has
stabilised tapping the gauge with a knuckle occasionally. Then start the
engine and get it charging, and if the fuel gauge goes up then the stabiliser is
faulty.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>If the temp gauge started heading for H as soon as you
switched on the ignition then the blue/green wire to the sender is shorting
out. But if it only starts rising once the engine is running it's more
like something causing excess heat, perhaps low coolant causing boiling, other
than that the sender may have failed in an unusual way.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>If the tach stops working but the engine continues to run then
it could be a wiring problem or an internal fault. For the former either
loss of the 12v or earth supplies to the case, or if anything has changed with
the ignition coil wiring the power to the coil could be bypassing the trigger
circuit in the tach.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>PaulH.</FONT></DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV><FONT size=2></FONT><FONT size=2></FONT><FONT size=2></FONT><BR></DIV>
<DIV class=WordSection1>
<P class=MsoNormal>#1 – tachometer – after working sporadically, the tach in
my ’71 B/GT has finally quit completely.</P>
<P class=MsoNormal>#2 – temperature gauge – until we started it up this
spring, the gauge has never been above “N” (except for one long uphill crawl
with a loose fan belt). Now, after only a few minutes at idle, it went
rapidly to “H”.</P></DIV></BLOCKQUOTE></BODY></HTML>