Starter won't engage with key

[TwinBridgesOK]

Have a 2000 718 Vanguard, unable to start without jumping the solenoid, tried new PTO switch, tried an older starter switch from my another 1999 parts mower, new solenoid. Most of my safety switches have been bypassed, however noticed something different happening with the emergency brake. Even with PTO off and arms out, it stalls engine when engaged. No fuses blown, however, wondered if there's an inline fuse I'm not seeing. Appreciate any help

 

[bertsmobile1]

Once you have butchered a wiring system you are on your own as we have no idea about what you have done.
The starting solenoid needs a power feed to the trigger and a ground.
The latter may be through the body or a second wire .
So you test it by energising the trigger circuit.