Have RV Questions? Ask an RV Mechanic Online.
Does it work on shore cord or is that the problem? It won't work on the inverter/charger. That doesn't produce enough power. IF I am not understanding your question correctly, please let me know.
That is usually a transfer switch issue. That determines which power source will be hooked up when you have more than one. If the contacts get burned or it shorts out, it gets "stuck" in one mode and won't switch over to the other. You can test it with a small digital multimeter like you can find at most hardware stores. About $20 and easy to use. I can direct you and over the phone would be a lot easier and quicker. Let me know. If you do need a new one they are about $200 and it takes about an hour to replace it in most instances. Hope that proves helpful here. Please get back to me if you need more as all follow ups are included in our fee.
Did you get meter so we can do some testing on the transfer switch?