I bought a 2021 Coachmen Sportscoach. I believe Jaboni set up the solar system (100W s. panel on the roof and Victron PWM 10A charge controller in the basement near the batteries). Question: Why isn't the solar panel registering on the charge controller? I took the two + - leads off the controller and receive 19.2 V on my multimeter. Yet when connected, it doesn't show the solar and thus not charging the house batteries.