Hi John
The ignition warning light is not on when the engine is running but is on when the ignition is on and the engine not running.
The Alternator is Remy remanufactured.
Have tried connecting a long jump lead from the alternator case to the battery negative. The battery is 12.3v when the engine is off or on. Get the same voltage across at the alternator +ve to the alternator case.
Cheers Steve