[Sergio]

The cut off switch is probably the "limit switch" in the FNR.

Assuming the backup buzzer is working, You can easily test that switch by putting the cart in reverse, if the buzzer makes a sound then the "cutoff switch" is working.

While any switch can go bad, in case of a short like you did, the destructive event happens on the contacts of the "making" switch (Stop switch in your diagram) and not typically on switches that were already closed.

If the buzzer works but you don't have 36v on the Solenoid Red/White wire when the pedal is pressed, the "stop" micro-switch inside the pot box is damaged.