Strange problem. teardrop is back from major rebuild, and a good bit of that was electrical. We have a 185W high voltage panel that typically puts out 35+ volts at the Morningstar Sun Saver MPPT controller. I have the remote meter which tells me the battery voltage and the solar panel voltage and the reading is 9V. I use my VOM multimeter and sure enough I am getting 9V at the controller I disconnect the Anderson Power Pole and am reading 35V coming from the solar panel, clean contacts etc still getting 9V at the controller when I plug it back together. Cut the wire removing the Power Poles (thinking that was thee problem) and wire it to the controller, the voltage when connected and under load is 9V. Pulled out a new (spare) controller. same problem! Connected a 25W panel I use for maintaining the battery. Everything works fine and read 17.8V at the controller.
I am trying to figure out likely cause.