Yeah. Screw flashing codes! It's not a 1980s digital watch π Do you happen to have a USB outlet fitted in your plane? To keep things light, I put in a small 2 X USB outlet (25 or 30mm hole from memory). But I really installed it for the digital voltmeter built into the face π. I also noticed my radio has a voltage readout but it's not easy to see.
Anyway, once you have everything sorted, take note of what voltage reads when everything is working properly, in flight. Otherwise you have no baseline to compare. At rest a lead acid battery is roughly 12.4v. Mine charges at 14.6v on the USB meter, 14.4v on my radio. It doesn't really matter what it says, 14.6v, 53 bananas, 37! Etc. if it's something less or more, then start thinking about what's going on. On my plane, I've decided anything less than 14v is noteworthy. And since 14.6v is pretty high, even a smidge over that warrants attention.