A couple other points may help restore it as well. This is the drawing for the 12Volt chassis batteries and how the coach and chassis fit on the racks and get wired/cabled:
One of the first issues may be to sort out which options were ordered when new as it involves how many batteries were there! So looking at the small info "bubbles" below the drawing can help sort the question of what to expect.
Top right of first page has a detail AA which has a bubble 22W. To find what that option is, go to the list at lower near right side and find 22W gives you two batteries! So match what you find on cables, etc. to the correct drawing for that? Look really close for the positive (+) and negative battery markings on the drawing as they are dim but there!
Don't try to sort how to wire for two if it only came with one, right?
A second point which may help, if the ID tape has not fallen off is the way Winnebago labeled them when new with tape near the cable ends to match this list:
Total wiring section here:
Good luck on the project!