[charby]

I had a similar issue with my former TT, the previous owner replaced the charging system with a battery charger. The switch on the charger was on 2 Amp, rather than 10 Amp. I had dim lights and battery level was not at full when plugged into shore power. Once I made the switch to 10 Amp, the lights brightened and battery came up to full. This may help you check the charging system.