I feel your pain and yes, I also agree with not wanting it to go to a shop!
But there is one good thing about Winnebago and they do try to post up lots of info to help us sort things like this.
For plumbing there are two sites to know about.
Plumbing, older style line drawings that can help at times:
https://www.winnebago.com/Files/File...m/Plumbing.htm
But I use this interactive parts catalog far more as it lets me sort down to what part, plumbing , electrical, etc and then go to drawings where I can "look through walls" and turn it all kinds of ways to get a better closer view.
https://catalog3d.winnebagoind.com/menu/Parts.htm
It takes some learning curve but it is great for getting a good idea of where and what we bought!
https://catalog3d.winnebagoind.com/menu/Parts.htm
Looking at this, I'm not seeing the same as you describe! You may have a far better way to tell what you are seeing than I do. Drawings are a help but not a total solution!
I see the fresh tank as being near center of passenger side standing upright. The overflow appears to come out the top and drop almost straight down to underneath? Not what you are expecting if I read correctly?
Maybe take a look and see what it tells you?
![Thumbs up](https://www.winnieowners.com/forums/images/smilies/thumb.gif)
Hints on using!
Once you get to the part (fresh or holding, etc.?) click on which angle to view from. Then before zooming, click on the symbol bottom left and one of the parts you want to keep as center. Then you can move, turn, zoom etc as you want.
Notice the yellow color of the tank? That is after clicking and it pops it up on the list at right for ID. Or if you know the name, click it and it shows yellow on the drawing. clicking the item on list repeatedly will make it flash on drawing as a way to find it if we know the name but not what it looks like or where !
Click this snip for better view!
See what you make of things and shout back if I can ease the learning curve, etc.
Note that this seems to be very good at actually showing even the small parts like el, so we have a good chance at spotting possible fitting problems to may have frozen, etc.