There are two models of that year, make and floorplan. early model has a 1 as 7th digit of serial (not VIN!) number and later build has a 2There are small differences in each but the basic plan for this section is much the same. Outside near left side front, there should be space where the solenoid (relay) and a coach battery disconnect relay are hidden in and behind a fuse panel.
You may be able to peek in to see these parts. Early build is horizontal to RV side, while later build shows panel is vertical to side?
But both look the same for function and wiring.
This solenoid is what ties the two batteries together to let the engine alternator get some charge across to recharge the coach batteries while we drive to the next site! We can also use a dash switch to get a "jump start" from the coach to a weak chassis battery when we push and hold the dash switch!
View attachment 1338934
When wire LR gets 12volt from engine running or switch pushed, it closes contacts in solenoid just like a light switch! those contacts connect chass (green line) battery to coach (red?)
Power from coach batteries is always hot at left side of the coach battery disconnect relay, This relay is controlled by the disconnect switch. Near door maybe?
Main point is that the blue marked items ARE cut off when this relay is open!
But see how the red coach battery is always left connected to the Wire marked GJ? GJ feeds safety items that are still left connected. That safety stuff will eventually run the coach batteries down if we are not alert and do something to stop it!
You may have a tiny little LED on the propane or CO detector? It may have to be dark to spot it! But it likely stays on when the disconnect is opened, so that can catch you!
Converter for charging is also in that blue group, so being plugged doesn't get charge if this relay is opened!