You ve tree wire from throttle and tree from break , all two goes to brain.
The are 5v supplies by the brain ,thé brain itself is supplied by 36v from battery .
You need a new controller with its display from AliExpress .
Cut the throttle and break wire, original brain goes to trash. Re wire all (not the orange connecter from battery , that s i don’t Know ?)
On controller you ve got one 4wire connecter , that s 5v , ground, break and throttle signal..
on controller you ve got a 3big wire that phase of motor, and 5thin wire that are the hall sensor (5v, ground , and tree hall feedback) so hère is thé biggest challenge 3wire motor, that can be switch itself( that done 6possibility) and the 3wire from hall( that done 6possibility too) so 6x6 done 32 possibility just to good wire the motor.. if you done this , the last Step is easy.
My last challenge it s to change thé tree wire from break that give a proportionnal voltage to a two wire switch that give ground to break wire controller .
I hope i ve helped.. To view images REGISTER or LOGIN for full access.