As noted by others the most frustrating part is the lack of documentation. You have to reverse engineer by taking the controller apart and following the wires. Even then it's a bit of luck to figure it all out. Once you wire the controller correctly it's an impressive DC motor/Controller for a DIY project. This motor has a lot of kick. Very happy with result, and has been great for the first couple days using it on a DIY go kart I've been building.Addendum: After figuring out the wiring I ran across the above picture of a similar product. Surprisingly, it appears to be the correct wiring diagram - correct number of wires, correct wire color, but use at your own risk. Hope this helps save another buyer some frustration. Good Luck!