Forgive me if I am insulting your intelligence but "ground" will be B- on your controller (the terminal with the long bolt). If you have already reconnected your batteries you'll want to disconnect them and discharge the capacitors in the controller before removing the ground from the...
Your controller goes to a Club Car model DS 48 volt made between 1995 and 2005. If you're looking for wiring diagrams look for the powerdrive electrical system.
The purple wire is ground for the throttle (Club Car's V GLIDE, POT or MCOR).
The red/white wire goes to the middle limit switch on...