[Richard]

If I could just weigh in with a tangent comment based on my experience. If the coach has the monster oil cooled alternator, this does not apply.

But if you have a Leece Neville or the Penn Tex alternator, even the ones rated at over 300 amps, charging a depleted house bank repeatedly with the alternator does lead to alternator failure. And to take that further, I have taken the isolator out of the circuit because I have lithium batteries. Perhaps my experience was unique, although years of following RV forums has numerous stories of alternator failure, so your mileage will vary.

If you use the coach pedestal to pedestal, and the only purpose of the isolator is to keep the house batteries topped off while traveling, I don’t think that puts much strain on the alternator. If you boondock, and draw the house batteries down, then depend upon the days drive to charge them back up, you may invite premature alternator failure.

So it brings up the point of why do almost all Class A manufacturers use some sort of isolator? I put that in the same category as the transfer switch that will switch power sources with all the AC units running. It’s one of those situations of just because you can, doesn’t mean you should.