Electric Wheelchair (Cranbourne RG21)

My mum has a Jazzy Air 2 electric wheelchair. It stopped working in a raised postition and the lights indicated a controller fault. She bought a new controller and her husband fitted it. It's still showing the same fault. She doesn't think he's wired it properly. It's free to whoever would like it for spares or repair. She just wants it gone ASAP. It can only be moved on free wheel.