HA, i think they all came broken from the factory. I've never seen one that deflects like you think it should.
they do actually work you will see the needle move Very slight towards the Charge side of the meter when the engine is running, and if you flick the lights on the meter will flick just a little towards the Discharge side.
now if there was a major short that meter will defect to Discharge big time.
I remember i asked about this same thing years ago, nobody had a solution. Mine works as described, very slight movements towards C and D. at every car show I've asked people about it, everyone seems to work the same way, i have never seen a NOS unit to compare to it.
if you are concerned about your alternator you can get a alternator tester for about 20$ and it will tell you the condition of your battery and alternator when the car is running, you can also use a voltmeter, record the battery voltage with the engine off, and then note a positive increase in voltage with the engine running, and the voltage will raise up a little as the engine rpms go up.
