there used to be a GM wiring book for the P30 chassis, specail order item
about 12" by 24" and roughly $90
it covered all the chassis wiring for all variations of the RV p30
nothing in there about the RV house section
as that is done by the builder during construction
you might try a Cobra RV users group/forum
and see if they have any of the info you are looking for
generically most motorhomes have similar setups, power center, etc..
most mfg DO NOT document wire routing (where it goes thru the RV), colors or connections and circuits are not usually numbered and listed , in away
that they can tell an owner exactly where to look for a certain circuit junction or wire route
there are exceptions, winnebago and safari both have schematics available
but for safari those only show how the connections are wired, but not where the wires are run thru floor wall or ceiling
i don't know how much info winnie drawings have
many of the other mfg have nothing