Basics: If the tires are older than 5 years old by date codes imprinted on tires, they should be replaced regardless of tread depth or new appearance for your safety.The brake fluid should be flushed and replaced and front brake flex hoses replaced if they are old and brake system serviced as needed again for your safety. If you see any yellow/green stains or smell ammonia on fridge cooling system parts inside the access compartment, the fridge needs a new cooling unit or new fridge. Your house batteries should read 13+ volts when you are plugged into 110vac "shore power" using your multi-meter. If not, your converter/charger, battery connections, or batteries may need attention.
Your house batteries are kept charged by the converter charger when rig is connected to shore power or when generator is running, or when you are driving by the engine's alternator. Your appliances operate on a combination of 12 volt dc and 110volt ac power and some on propane. It pays to get familiar with the complete electrical system, including fuse and circuit breaker panels, battery connectors, maintenance of battery electrolyte levels, house battery disconnect switches, etc. Lots of RV user info available on You Tube.
Get a generic RV operation and maintenance book from Camping World, etc. and a Chilton's overhaul and maintenance manual for the year model van that you have.
