Originally Posted by Bud
Can you Not charge the rv battery for a month and then start the generator without starting the van's engine?
On a single battery, possibly a wet cell if same as original, of about 90ah. I don't think the 170 had a second battery option then.
If the 12v power to the coach was off for the month, it probably should start the generator as long as the generator starts fairly easily.
If the 12v coach power is on, the detectors would kill the battery in a month of sitting without charging or driving.
Of course, the running of the van engine to help start is dependent on the isolator being functional, which should also be checked as well as the circuit breakers from the isolator to the battery.
The OP may want to download the Roadtrek electrical simulator to be able to see how it all works, for a better understanding of it all.