:welcome:
Sounds to me like there is a problem in the wiring which caused your ignition switch to fail in the first place.
Connecting B + S + A1 should not cause the fuse to blow on a mower with wiring in good condition.
Next the plug shown in your attachment was not the one fitted to your mower.
There is a circuit diagram in the back of your owners manual.
If you don't have it, you can download one free of charge from Sears or a dozen manuals sites.
To help us work through your problems we need the Craftsman model number from the tag under the seat.
Most likely will be 917.???????
While the basic wiring circuit on all tractor type mowers is the same, there are subtle differences.
Some switches can simply be unpluged, some have to be jumped.
This has been done to prevent people doing exactly what you are trying to do.
When faced with a constantly blowing fuse, I fit a circuit breaker in the fuse holder then start undoing plugs one at a time till the culprit is found.
Contrary to popular belief no one has ever died because their grass was not cut, but a lot of people have died trying to do it when they should not.
And the most common reason for fuse blowing is the battery connected backwards
