Hi. New here. I have a 2001 hitachi ex35u mini excavator with a Isuzu 3LD1. I’m doing a small restoration on the excavator and have the engine out to paint it. I noticed the crank pulley can be spun independently from the crank. There is resistance but it is not “loose” and doesn’t wobble. Also the battery light has been on since I’ve owned it the last year but never any charging problems. Is this pulley not supposed to be able to spin independently? Could it be the pulley slipping causing the alternator to not spin fast enough to keep the light off. This pulley also spins the belt that spins the fan and this engine has never come close to overheating at all. Thanks for any help.