Use a bigger bulb like a headlight. Should see amp draw (movement) in one direction on gauge. Reverse terminals on gauge, should see movement in other direction on gauge.
Hookup Example: (which you did correctly) Bat + to gauge Term 1, gauge term 2 to bulb 1, bulb 2 to batt neg. Don't use the pick test light bulb this time.
Whatever you do, just quickly touch don't clip it on both battery posts.
The fact you tested several and got NO reading is confusing to me. All I can think of is you need a bigger test draw (bulb). A super small fraction goes thru the windings, the rest is shunted. Gauge tolerance not reading a pee wee bulb draw.
