This is quite a common problem, and the most likely causes are a fault or failure with the charge controller or inverter or a panel in your array that has failed. To troubleshoot this issue, you will need to test the inverter, the charge controller, and the solar panels to determine where the fault lies. To do this, you will. This is the most straightforward step, as most inverters have warning systems and indicators that activate when it detects a fault. If you find there is no voltage, check the inverter and see if the. You can test the charge controller using a multimeter. Connect your multimeter carefully to the positive and negative outputs and see whether there is a voltage reading or not. The controller regulates the voltage and amperage to. Aside from the above, high temperatures, shading, panel damage, and faulty connections can cause a lack of voltage from solar panels. Because solar panels in an array are connected in series and if one fails, the whole system goes down and there will be no voltage or current as a.