Hope this helps.
I ran into this type of problem while camping at Twin Lakes CG. in Colo. A camper came over to our site and indicated he had a camper of the same make as ours and said he had a full tank of fresh water, but the pump would not pick up any water to his faucets. I went over to his site and found the clear filter bowl on the pump was loose. After hand tightning the bowl and opening a faucet to releave the air, the pump primed and his problem was fixed. Good luck, Tom-s