Continuity works but no voltage

Welcome to the forum MRCC1,

Obviously, solar panels need some direct sun on the panels. If there is any shading, it will dramatically reduce their output.

Under sun, and if using a "simple" PWM charge controller, the panel(s) should read near Voc (voltage open circuit) or 20+ volts if not connected/under load, and around Vbatt when connected and charging the battery bank (at the Vpanel input terminals of the charge controller).

So, I would disconnect the two wires at the Vpanel input of the charge controller, and measure the voltage there. Note the polarity, it is very easy to mix up positive and negative connections. It is possible that if you have +/- reversed on the charge controller, it may "short out" the panels and read zero volts (I do not know, just guessing).

If you still read zero volts with the Vpanel terminals disconnected, go back up to the solar array and measure the voltage up there. If zero, then disconnect from the RV wiring and check again. Make sure if you have several panels in parallel, that they are wired + to +, - to -, etc. (if wiring in parallel).

Solar panels are not really "solar batteries" in the sense that they output 17.5 volts at any current level... They are "current sources" that will output (approximatly) X.X amps based on the amount of sun hitting the panel (100% sun, then 100% of Imp rated current. If 25% sun, then 25% of rated current). So the measured voltage from the panels depends on the amount of sun, amount and type of load, etc.

-Bill

At least you found the problem, and hopefully fixed it.

Take care,
-Bill