For a start, check out my tech tip on Mark Olsen's Tiger web page.
The fuel and temp gauges have the same internals, but different faces.
The same sender resistance should produce the same pointer angle on
both. You could swap the sender leads and see if you get the same
pointer angles, to help with troubleshooting.
The stock voltage regulator produces a switching waveform at it's
output, switching the power on and off a few times a second. An
average over time of this voltage will come out to about 10 Volts. A
cheap analog voltmeter ought to have it's pointer bouncing around if
you try to measure the 10V. If is stuck ON, you will read 12V, rock
steady, and both gauges will read high.
Your temp sender could be failing, too. Though, when mine failed, I
started getting lower temp readings. If you have an ohmmeter, watch
the sender resistance as your engine warms up. Use my chart to
estimate what the resistance should be when your thermostat opens.
Voltage regulators can seem to fail if they loose their ground, which
is through their mounting brackets. Remove yours and clean the metal
underneath, and put it back, if you don't see the switching.
As I stated in the tech tip, DO NOT try playing with the meter
calibration screws. Without the proper calibration procedure, a
mystic ritual developed by the manufacturer, you have no hope of
making it any better.
Stu
|