There may or may not be a battery isolator in the coach. Seems the "specifications may change without notice" clause often applies.
The easy way to check is to put a voltmeter on the coach batteries when the engine is off... record the voltage, then start the engine. You should see around a 1V increase in the coach batteries with the engine running if they are charged by the engine.
That 1V increase comes from the alternator charge function.
If you don't see a voltage change, there is either not a battery isolator on the RV, or it's defective.
The only thing that works on a RV is the owner...