probably craftsman.com
Try the Craftsman web site.
Use the related link below for your manual.
You can find a wiring schematic for an 88 Craftsman GT ride on lawn mower at various tractor supply stores. You can also find it in the mower's owner's manual.
You can order it from Sears online for about five bucks. I have been searching on line and can't find a free download either.
If it is in fact a 917.377410, then try the link below.
go to the sears website
amanonisang@hotmail.com has one.
You can go to sears .com an put in the model number.Then you can download your manual
Try from Sears at Manage My Home at the link below:
Manualsonline.com now has the manual as a PDF File for anybody to view or copy free!!
http://www.searspartsdirect.com/partsdirect/index.action
Online. See the link for help.