How to program the mode buttons.
1. Power up charger before installing the charger and press the mode button to select the type battery or the type voltage you need. make sure to pull fuse first to eliminate damage to the charger.
2. If already installed you can pull the fuse from the bank you need to program from the positive side while charger is pulled in and press the mode button to program then replace the fuse.
How to tell if charger is working
Non waterproof blue chargers have a red light and a green light when plugged in and not charging. If both light s are red then the charger is working. You can check battery app to confirm it is working and how many amps it is charging the battery.
Waterproof models have multiple lights to show state of charge. If all red lights are on and there is a green light it means it is not charging. just red lights on means it is charging again check app on battery to confirm charging.