Wireing diagram for a school bus

What make of bus and what chassis is under it? Which control console does it have?

Indeed -- usually there's a "data plate" somewhere on the bus that gives all sorts of gory details -- everything a mechanic would need to know if chassis or driveline parts had to be ordered, basically -- as well as contact information for the body maker. Most school buses of my acquaintance have it somewhere forward and up, on the passenger side.

If it's an nth-hand bus that someone has converted into a hippie motorhome or somesuch, the plate might've been removed, but you can probably still find the manufacturer's name someplace, whereupon you'll probably find that (perhaps for a fee) they can go through their records and get you a lot of data, manuals, etc.

This degree of recordkeeping is partly for maintenance and partly for traceability of anything that is found to be wrong, and I think a lot of districts flatly wouldn't buy a bus without it.

See also this site and links therein:

--Joe