Re: ATF: Sundance - Converter Replacement
You don't say which model of Sundance you have, but in my 2011 245RL, it's located in the power enclosure with the fuses and circuit breakers. Take a look
here.
That being said, since the lights run off the battery and the converter charges the battery, it may not be the source of your problem. It sound more like you have a loose connection, or a bad battery. If you know the battery or batteries are good, I would start by looking at all of the connections in the power enclosure including the wiring that goes back to the battery. When the converter is on, you should measure about 13.4 Volts DC at the battery with a volt meter. That reading would generally mean it's unlikely to be the converter.