Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
Hello, my name is***** sounds like your starter has failed and the extra voltage/amperage from battery charger is over powering worn starter allowing it to work. With a multi meter verify both wires at starter are getting at least 11v while trying to start, if so this means the starter needs to be replaced. It is possible the new battery is problem too, you can monitor battery voltage while trying to start and if it drops below 11v when trying to start this would mean battery has a problem. Let me know how it goes or if you have more questions, thanks.
Then it sounds like starter is the problem, verify it is getting at least 11v while trying to start and if so then replace. Let me know if you have more questions, thanks.