The way if works for us, is that I start the engine, let it run for a minute or two then hit 'high' idle from the rabbit switch on the dash. Now at high idle, I go to the bedroom and start to close the slides.
Our slides have air seals, so I hold the button to close, the seal deflates and then the slide moves. I have four slides to close. Once all closed, then I go out and disconnect the sewer, water and electric.
Then, we are ready to roll. I would say that it takes 12-15 minutes for all of that to take place. Our engine is loud, especially, if I have the dash air on. The MONSTER radiator fan will pull you into the coach if you are too close (almost, LOL!).
All I can say is, 'it is what it is'.... I can only do things so fast so if I'm running the idle too long, well , it's too long.
MM.
