My 2003 was wired on the inverter and there was a problem with it. When you were running on the inverter there was a feedback to the shore power cord. I measured about 93 volts. Winnebago said it wasn't a problem because the available current was so low on the shore power cord. Yea right, when it was wet outside and you grabbed the shore power cord and touched the prongs it bit you. I complained to Winnebago and the solution was to move the ref off the inverter, and so when shore power, or generator power was not present the ref switched to propane.
I also have a 2000 watt inverter, but it is a discontinued model. It is easy to tell if you have an inverter like mine as the case is black.
If you have an inverter like mine you probably have the reason the ref is not on the inverter.
2003 Ultimate Advantage