The AC-60CR includes self-diagnostic alerts. Here is the official troubleshooting table:
The is a heavy-duty, manual battery charger and engine starter designed for 6V and 12V lead-acid batteries. Because it is a manual charger , it will not automatically shut off; you must monitor the charge and manually disconnect it to prevent overcharging and battery damage. Key Operating Instructions autocraft battery charger ac-60cr manual
For safe operation, follow these steps to connect and use your AC-60CR charger: The AC-60CR includes self-diagnostic alerts
Sellers of used Autocraft chargers sometimes include or scan the original manual. it will not automatically shut off