The coach manufacturers manuals are unlikely to help you repair anything - many of them are inadequate even to find and operate everything. You can get 3rd part Rv maintenance guides, though, that will help with common diagnosis & repairs of the water & electric systems, appliances, etc. ONe of the best is called Rv Maintenace 7 Repair by Bob Livingstone. Its available through Amazon.com, Camping WOrld and many Rv stores and even book stores. See
http://www.amazon.com/gp/product/0934798451/104-6016870-3980725?v=glance&n=283155
And here's a free website with many RV maintenance tips: http://www.rvrepairmanual.com/index.html