I can't figure out what is wrong with our BlueSolar MPPT 75/15 charge controller. Ideas appreciated. Situation: The yellow LED charge indicator light isn't coming on at all, even though there is sun on the PV panels and the PV open circuit V is 19.45 V. When the PV panels are connected to the PV terminals on the controller, V across the PV terminals is 10.74 V, while V across the battery terminals (with the battery connected) is 10.87 V. The fuse is ok, and the green power light remains on. All wiring is correct polarity. The only load is low-power LED lights, 12V DC, totalling about 25W. The controller is about 4 years old. Load voltage is zero, but I think that's because the low voltage load disconnect jumper is set at 11.1 V.
