We have a 2004 H/Rambler. If you think the engine might not start you could use the Boost switch and try to start the generator; It's only about 15 HP. If the genny starts then you can use the boost switch to start the engine. To do that, let the genny run for sveral minutes then hold the boost switch down for a minute or so. Do that sveral times (with the ingnition key off) then try to start the engine. If you must use jumper cables, use them to start the genny, it takes less current to start than the engine. If your coach is like mine the genny starts from the house batteries, not the engine batteries.
Jenny & Bill
2004 H/Rambler Ambassador 34PDD
Cummins ISC330 Allison 6 speed
2003 Chevy Malibu Toad
Our new Yorkie, Daisy.