How to Troubleshoot a Craftsman Battery Charger

Plug the battery charger's power cord into a live alternating current (AC) outlet if no indicator lights appear. Ensure the outlet works by testing another appliance in it.

Inspect the clamps to ensure they make a good connection with the battery terminal. Re-seat the clamps if they are not secure.

Select the appropriate charge voltage for the battery. The battery will not charge if an improper voltage is selected.

Disconnect the charger if the "Charge Complete" indicator is lit. The battery will not continue to charge after the unit determines it is fully charged.

Wipe battery fluid from the clamps. Dirty clamps can prevent the charger from making a good connection with the battery.