Hopefully you've found your pump. I checked the Winnebago diagram and it does look like it's in front of the fresh water tank and may be inside a cofferdam. My 2008 Voyage 35L (built latter part of 2007) is a little different, but available in the second compartment behind the steps.
The diagrams and pictures show two different locations for mine. I can't help but think they may vary somewhat during manufacture. Take a couple of pictures and include them and I bet somebody can point out the most likely location.
__________________
2008 Voyage 35L, Allison 6 speed auto and GM Workhorse 8.1 gas
Thanks for the reply. Your post started me thinking about "inaccessible" spaces.
In the third compartment from the front which is directly below the fresh water tank is an access panel (circled):
However, to remove or work on the pump you need to remove the exterior panel (arrow). Removing the panel is not difficult. You remove eight screws from the plate that the panel is attached to.
Here's a close up of the fresh water pump compartment
I replaced the exterior panel and placed a heater in the rear compartment. I believe that my pump is frozen. It was working when I turned it off Friday night. I should know in a couple of hours.
They make these plugs that only come on when the temps drop and a heat tape that you can wrap around things like down spouts to keep them from freezing. Perhaps you may want to consider something like that as a solution. It will click on automatically and turn off automatically that way.
__________________
RUSTIC is good.
Kudos to those who make Local, State & Federal Parks & Campgrounds possible and to those picking up the slack by Providing Private Campgrounds.