Chaz, first of all understand that I was referring to the "Voltage stabilizer", that is used to regulate the voltage used just for the gauges on SIII thru SV Alpines, not the main voltage regulator. As you see the regular output of the alternator or generator varies between 12 and 15 v . This variation is not a problem for the ignition, lights, radio , etc, But it would cause the temp and fuel gauges to read different depending on the state of charge on the battery. So on the SIII thru SV they added an extra "stabilizer" to stabilize the voltage used just for the two gauges, Temp and Fuel. The original factory stabilizers worked on an On/ off method , turning on and off about 2 times per second to produce approximately 10 V average, regardless of whether the full battery voltage was 12 or 13 or 15. And the gauges for the SIII thru SV were designed to operate at that 10 V.
The late gauges work fine with this on off stabilizer, because they work on a thermal principle and the needles always move quite slowly.
The earlier Alpines had more complex (and expensive) design of the gauges and relied on a complex "bridge" circuit inside to make the immune to the voltage changes, and thus did not require the stabilizer.
When you first turn the car on, does the Fuel gauge move quickly, almost instantly, to the correct indication? If so, it is almost surely the early S1 , S2 type, and I have no idea what the sender resistance should be. I only know that all catalogs show a different sender for the S1, S2 cars than the S3-S5 Alpines. In general, if you see the needle on either Temp or Fuel gauge move quickly, like jumpy, they are almost surely S1, S2 gauges,
If, on the other hand they always move very slowly, even on a warmed up car, where it sat for a few minutes and then you turn on the key, then they are almost surely S3 thru S5 gauges, and require the use of the "stabilizer" to read accurately.
Again , I say I do not know the resistances appropriate for S1, S2 Gauges. But the values noted earlier in this thread were about the S3 thru S5 gauges.
If you do indeed have S1 , S2 Gauges, and can tell us the resistances for different readings, say, 0, mid scale, and full scale, you will be providing new information I have not previously seen on this forum or anywhere. That would be neat info to have.
By the way, all the late series gauges I have seen 3 have pairs of TINY dots to indicate their electrical calibration Zero, Mid-scale and Full-Scale indications, regardless of the markings for Fuel or Temp numbers. I would love to know if the S1 , S2 gauges have similar markings, and those markings are what you should use to determine the resistance required for the three level indications.
Tom
