Join Date: Nov 1999
Location: Central California, USA
These gauges read "differential voltage" and give you an estimated amp reading.
A normal old fashioned ammeter reads amps by reading voltage drop through a "shunt" It's the brass bar across the back of the gauge. It reads the difference in volts between each side of the shunt and the scale is calibrated in amps.
The Camaro amp gauge reads volts at two points on the car's wiring harness. I assume one near the alternator, the other near the battery. The Camaro's wiring harness is the "shunt" the same as the rear of an ammeter works.
It might be interesting to measure with a digital voltmeter at your ammeter and compare the readings to another car. Perhaps your gauge has a poor connection somewhere. If the other car has good movement with more difference in voltages, then the "problem" is in your cars wiring harness, not the gauge.
I've just learned this stuff myself.
The older I get, the faster I was!