I own a Tricycle for taking my old dogs for rides. I put an aftermarket motor on and it has a 36 Volt system, there are three wires from my controller = yellow, blue and green. My friend checked with a meter and says the voltage appears to be good from the batteries. His guess is that it is a controller problem. I have pictures of the set up. With fully charged batteries and tested, still when I move my throttle to add power I hear only a faint tapping sound from the motor and no movement. During my last ride it felt like the motor was trying to turn the wheel backward? I appreciate your help.