WD - the Solar Panel controller has a Red LED light which should be lit, when the solar panels are getting sunlight and putting out power, if no light, the controller could be bad. There are several good solar controllers out there which are much improved to what WRV installed.
FWIW - if you have the 10w solar cell WRV used for a time, cut the wires to it, as it usually failed and looking at it you can see were cells have shorted out, this will put a drain on the chassis batteries, and cause them to fail prematurely, because the charger try to charge them all the time. I had this almost happen to me, found out about the shorted panel, and cut those wires so it would not do that anymore. I have one panel of 100W on the roof and it seems to work fine when the sun shines on it. I clean it about once a quarter, unless we have our rig in storage.
Monty & Janet - 2007 Alpine APEX 40 MDTS
S/N - 75715 - Retired - Master Certified RV Tech