Our 2004 26Q Tioga water pump is located inside the rear dinette seat cabinet. Just remove cushion and take out four phillips screws and lift out plywood cover. If the same the water pump setup, pump, filter , tubing plus converter/charger and wiring may be there. Good to remove front dinette plywood cover and see what's in there too. BTW, hot and cold water shutoff valves may be accessible, with difficulty, behind a panel on the outside of bathroom wall. If you DIY you will need to get familiar with this and house battery setup.