after making basic checks : FU2(250A) and wiring. does the direc.contactor close?. do you have right inputs to controller?
1- key sw.(pin 1)
2- brake sw(pin 2)
3- B+ coming from contactor coils when key sw and brake sw activated. (pin 18 and pin 19).
also make sure you have correct resistance at pot. terminals connected (pin 14 and pin 16) around 0 ohms when grips rested and about 6 khom. at maximum fw or rev.