Triumph Repair: gauges, british cars, test light

Question
I have a 1978 Spitfire.  About a week or so ago the tach, fuel and temp gauges all quit at the same time.  I checked the fuses all good.  I looked at the wiring diagram and decided to replace the Voltage Stabilizer located on the back of the speedometer.  That did not fix the problem.  Do you have any suggestions what to check next?

Answer
Hi John,
Use your diagram to see where they all get their power from. Then use a 12v test light to trace the trail of power. Before you replaced the voltage stabilizer did you check to see if it was receiving power? The stabilizer drops the voltage to some of the gauges but not the tach. However most British cars supply the tach and the stabilizer with power from the same fuse. So you not only need to test (before you replace) a fuse, you need to test for power in and power out of that fuse. From what you say I would start at the fuse with all the green wires on it.
Let me know,
Howard