Ed,
I do understand that manuals can be outdated, or otherwise not representative of the coach sometimes. The manual, and I guess I'll have to find it, states the same thing for both the generator (except that it does the preheat automatically before its starts the generator - about 5 second delay) and the C12, and that is that a small diesel heater does preheat the diesel, so they state that you do basically as I have done. I too have a preheat function for preheating the coolant in my C12 by way of my oasis combi.
Like I said, the manual may not match what is actually going on, but then too, my gut feeling is that things could also have changed between our model coach systems. I'll try to find the manual but I believe it was in the Beaver Owner's manual (not the caterpillar manual).
Thanks for the info on the ignition solenoid. I have one if I need one now, but am less likely to replace it now given that it would not resolve the issue about the starting.
As a further note to Adam, my chassis batteries are 1 year old, so I think its possible yours are fine. Just appears that they are slightly low, so like mine, they do start the coach, just not as nicely as you have that delay, the alternator then takes over, and if you stop along the road, then restart there's no problem. I hope that's the case, rather than having to purchase new batteries, which in my case didn't solve the problem - though one did test bad and that's why I replaced it, not because of this issue.
Thanks all,
Mike