Please add your make, model and year to get the best help.
Could that be the winterizing hose that sucks pink into the pump to distribute around the camper. Mine has an intake very close to the pump and has its own diverting valve.
Have you check your owners manual under "winterize"?
2017 SLX 195RB
2021 Jeep Grand Cherokee Summit L 5.7L V8
Andersen WDH hitch, Renogy 100 AH Lithium &
200 Watts solar panels from Renogy
Prev. '14 Jeep Grand Cherokee Overland, gas 3.6 V6