12 Volt Electrical issue?

Your house batteries are charged by a "converter" that converts 120volts AC to 12-15 volts dc to power your 12 volt dc devices and to charge your house batteries when you are plugged into 120volt "shore power". Charging power goes to your house batteries through heavy guage wires that connect to your converter Make sure that the wire connections at your converter are connected securely. Use the proper size allen wrench to tighten the connectors onto the wires. When plugged into shore power, measure the DC voltage at the house battery terminals, it should read over 13 volts if your converter is working and charging the batteries and the house battery disconnect switch and relay are working and there are no fuses blown in the house battery charging circuit.You will need to have a simple multi-meter and now how to use it to check voltages. If this is all Greek to you, take it to a trusted RV repair service for diagnosis and watch what they do. If it turns out that you need a new converter the Progressive Dynamics PD9245 is a good and popular choice. You may need new house batteries. I bought US brand batteries recently, they are considered as good as common Trojan brand but much cheaper. RV batteries are only good for about 10 years useful life if kept charged and proper electrolyte levels are maintained and your charger does not overcharge batteries
Learning about 12 volt systems and how to troubleshoot and maintain them in an RV is essential to pleasurable motorhoming.