re: #240 Dangerman

Sounds like something in the panel has gone high-resistance and is thus current-limiting the output. A high-impedance voltmeter pulls very little current so it shows a potential of 16V across the output. Anything that tries to draw more than a few microamps from the panel like your solar controller or your ‘power meter’ pulls the potential down to effectively zero. You’d probably get different readings from different voltmeters depending on their construction.

If it’s an individual cell that’s gone high-impedance then the entire panel is fucked. It might be the final connection to the array that’s problematic but I can’t diagnose that for you.