A 1 amp diode is usually for a 200a solenoid and a 3 amp diode is usually for a 400a solenoid.
And coil suppression is not as much an issue for the controller as it is your positive activation circuit on your cart. Ie: Micro-switches.
Your cart should have been equipped with a diode so if you kept your OEM solenoid it will still work as it did prior to the Controller replacement.
