I appreciate everyone's responses to my question. And if I do ever get those schematics of the pipes under this beast, I will definitely send them to the factory since they apparently are in need of help. When you ask them where something is or how it is built or how to repair it, they either don't want to tell us because they are heavily invested in Camping World and want us to go there for repairs, or again... they need help. By the time my husband finishes fixing our back bath black water tank valve (he already fixed the front one that fell apart), I'll give you his number so you can send for him to come and fix yours if it malfunctions! It would be cheaper than Camping World!!
I think we will buy one of the newer RV Repair books on Amazon and hope we can use some of the info. We are full-timers and the answer to every problem (and there have been a lot in 2 years!) can't always be "Camping World".