I did something dumb.... I was blowing out my AC water line and the rubber tip shot off down the hose and I cannot find it yet. I blew air from the outlet hoping it would blow back out. My question is, when you turn AC on is there a valve in the water line somewhere or does it only turn on the pump to the unit? When I tried to blow it out from the outside I did not have it turned on. I would have to lose 30 pounds to get through the access door to the AC unit. I am pretty sure I know the answer, no it doesn't have to be running.....

Can you try and suck it out with a shop vac????

Going to try my vacuum pump next! It's like a bullet rounded on the nose shot down the hose like a riffle barrel..

There are no valves in any systems i have seen yet. And as far as the pump power....its gonna depend on how it was wired by the installer......the "Normal" way is to have the pump activated by the AC unit when it called for a cooling cycle....but i have seen them wired up so the pump runs 24/7 when hooked to shore power....dont know why...
If its one of the pumps we make here (March Pump...most likely an LC-3CP-MD) and you lost the rubber tip on the inlet hose going to the pump, then its still stuck in the hose....or right at the inlet of the pump. We have a "spider" on the inlet holding the shaft in place for support that would block that tip from going any farther. If its another pump company then i cant say the same...And if you lost it on the outlet side of the pump going to the AC unit....then good luck cause i cant say where it would be!
If you are winterizing the system then make sure to actually RUN the pump so it pushes the antifreeze in to the cooling tubes...The 1.5-2" of tube that you see on the outside is misleading as the epoxy covers about another 30" of tube that bent up and wrapped around the motor! If you dont run the pump you wont get antifreeze in to the tube and you will probably have issues in the spring time! I get about 3 weeks worth of calls in the spring time of about 15-20 boaters per day with the same kind of problems from not winterizing it properly...