and i am fiddling with my 28. my wirings are all toast so i need to do an extensive re-wirings. no idea if motor is running. it has a knee controller assembly but i googled and checked online and couldn't see any wiring diagram. any one knows how to wire this assembly? have no idea what the two prongs are for (see 2 red arrows). would appreciate it if someone can educate me on wiring this knee controller assembly. thanks again.