Where OH Where is my water pump

I was looking at one MH that interested me at the factory, I think gulf stream?? and asked the rep. where it was so I could add a winterizing inlet. we looked all around, turned it on and nothing. has a worker come out from the line and he was stumped. it ended up being behind a standard hinged outside compartment door behind which was a metal panel that had to be removed to get to it.
bumpy