I discovered why Forest River (and other RV manufacturers) do not supply wiring diagrams to DIY types (or dealers for that matter); they don't use one.
From the looks of the underbelly wiring when I dropped it during my Horst Probe install, they just pull from the correct gauge spool of one or two wire when they make a run. There is no way to track down which wire does what, except visually. For example the left and right slide motors use the same green/yellow wires as the heating pads.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW