Trying to help out a fellow RVer. Has a 2004 ish HR Ambassador , no 12V at all, lights, furnace, water heater nada. I have an 07 but they are very different. Checked pedestal, inverter, turned both of...
No 12 volt at all implies nothing from either the house battery and the converter. There check what is common to both with a volt meter. Start at the distribution panel and move out towards the converter and battery.