We've had the same problem for months. Doug checked out the converter at the Travel Club Reunion and said everything was working... At least the converter and other components are. The battery still doesn't get a charge from shore power or genny. John has been hooking up our plug-in charger every time we're in camp with electricity. We have to run the truck to recharge when dry camping (or rainy conditions - we bring the charger inside).The Onan shop did a quick test directly at the batteries using a voltage meter. Truck running-power in. Generator running-no power. John checked the fuses in the battery compartment and said they looked good but maybe we'll swap them just for good measure. Where is the diode type thing and do you test it the same way?