CM, CM/R or DVM for C-Series not showing proper voltage
In order for one of the LCD displays for the C-series charge controllers to display the proper voltage, it is required that the jumpers on the display, as well as the controller, be set properly to the system battery voltage. The jumpers on the controller determine transition from Bulk to Absorption to Float. The jumpers on the display determine what voltage is displayed on the LCD screen.
Please see the attached graphic for jumper location on the display board.