If the controller has a key switch connector then a switch of any kind needs to be connected to it in order to turn the controller on and have it operate the motor. A switch is necessary and not a jumper wire because the controller needs to be turned off when it is not in use otherwise the battery pack will become discharged when the cart is not being used.
On most speed controllers the brake connector is optional to use and the controller will operate with nothing connected to it.
Thank you for the helpful info.
Hi, I have a 24 v scooter drive train that I'm using to power a 4 wheel cart. I bought a speed controller but when I wired it up, doesnt work. I connected the power supply , motor and throttle only because that's all I need. But I was told it's not working because I need to connect the key switch and brake. I dont have a key and I took off the brake because I dont need it either. How do I connect the controller to work?