I have a Craftsman Rider Model 917.252451
As I connect the battery it blows the fuse, every time.
I figured I would start disconnecting things to narrow down the problem. When I disconnect the "Engine Harness" (as its referred to in the electrical diagram) then I can actually connect the battery without the fuse blowing.
I don't know if this connects to some sort of coil or what?

Also, the connector I disconnected has a label M+G 140413 B, attached to it. Not sure if that would help?

Ok, last update, its not connected to the coil, I found the coil wire, still don't know what it is...

Have you replaced the ignition switch recently?

What motor does this have on it

Check the diode on the engine harness.