chevy van wet interior maybe heater core leak

Parts stores sell bypass caps (hose with no open end) pull the heater core hoses off engine and place the caps on, most times these are different sizes hoses and the caps come with 4-5 size caps in each package just ask the counter person where they are and get 2 clamps or if same size hose you disconnect one hose from both ends and run the other back to the removed hose's location and re- clamp or if hoses are similar in size use a short pipe that you run both hose's too and put clamps on it. Cut hoses back if desired to keep things neat.