Which is the problem: Panel(s) or controller?


New Member
Sep 13, 2021
Midland, MI
A couple days ago the charge controller in my motorhome stopped producing current to the battery bank after 6 months of no issues. Here is the quick run down:

*Rich Solar 40a MPPT controller
*4 x 200w 12v rich solar panels
*2 x 6v 250ah in series reading 12.3 volts
*Panels disconnected I read 12.3v at the battery terminals on the controller via multimeter
*Panels connected I read the same voltage at the battery terminals
*Panel input on the controller shows 88v at .5a with full sun and no clouds at 1:30pm (like an idiot I did not confirm this with multimeter, will do so when sun is out again)
*Controller error code reads E0
*Battery light on controller is solid
*Panel array light is slow flashing, and reads "Boost"
*I show no amps flowing into the battery, measured with battery monitor
*Battery monitor shows charge when using shore power, or when vehicle running
*Bluetooth adapter stopped working as well
*Disconnected everything from the controller and it sat that way for 3+ hours, reconnecting yielded the same results

My first inclination was that one of the panels went screwy on me, but I'll admit ignorance once troubleshooting beyond the basics. I can test each panel individually if needed, but I'm avoiding that absolute headache of a task unless absolutely necessary.

Any input or advice would be greatly appreciated.