The other factor here is "just what is" the design supply voltage of these gauges? I'm not sure anybody really knows. Seems to me the service manuals describe the original IVR as being a "50 percent duty cycle" so that would NOT be 5 or 6 volts on a running automobile, it would, rather, be closer to 7 volts
"Everybody" seems to be using 5V regulators. Frankly, I bought an RTE, and never bothered to check the output voltage!!!! when I installed it.
