AUTO-DETECT: WF-8900-AD MBAWF-8900-AD MBA Series
The WF-8900-AD-MBA Series Main Board Assembly will charge the 12-volt House battery if installed. A battery DOES NOT have to be installed for WF-8900-AD-MBA Series Main Board Assembly to operate. When a battery is installed, two reverse polarity fuses protect the MBA circuitry. The fuses are located along the left-center edge of the DC fuse board below the VCC+ lug. This Auto-Detect feature prevents permanent damage to the MBA from a battery connected into the circuit backwards. In addition to protecting the MBA, the reverse polarity fuses are the main connection between the MBA and the DC fuse board.