Small Engines (Lawn Mowers, etc.): Yard Tractor, briggs and stratton, battery cables

Question
We just got a Yardworks Lawn Tractor-Model 60-1824-0 (13DD688G515) with Intek 17 HP OHV Briggs and Stratton Engine.  It is a few years old and looks as if it has been "worked on" a few times. The mower was running and cutting, but when we tried to start it the next day,it turned over then nothing happened. The engine will not turn over and doesn't even make a sound. We are trying to find the problem, it's not the battery,fuel,spark plug,or selenoid.  Where is the kill switch located on the machine?  It looks like the wiring has been worked on too and we don't know how it "should" be! Is there anywhere we can find a wiring diagram that would show the proper locations? We have the Owner's manual and the engine manual, but can't seem to find what we need.  Do you have any advice on what to check for, or what may be the problem?  Thanks in advance for your help.

Answer
Are you located in Canada?  I did a search and looks like Yardworks is made MTD but distributed in Canada.

Here is a link to see if the parts diagram contains a wiring diagram.  You will need your serial number as well.

http://www.mtdcanada.com/model-search.asp

Did you dis-connect the battery cables and clean the post and battery cable ends with a wirebrush?

Eric