Hello. I have been all through the forum and found it very helpful. I needed a new motor since my son decided that it would be fun to off road on my cart. I order and got the D&D 501:3 (replaces D391 on their web site) since it was a drop in replacement. I put it in still no go. I did all the tests that I found here and on other forums and figured that the controller is bad. I jumped the solenoid, that didn't work. I by passed OBC that did not work. The cart charges with no problem. Battery pack was over 50. They are only a few years old. I tried a few other things also just cant remember right now. So I ordered a new controller and they called back and said that I could not use any other controller then the stock one with the motor. so they canceled the order for me. I call around and the stock controller for the cart is no longer made, just rebuilds. I called D&D and they said that it was never tested for upgraded controllers or ones that say they are for stock motors. It has only been tested on stock cart. Has anyone used this motor with any other controller without a problem? I don't need anything great just a controller that will work with it. The rebuilt CC controllers are $500.00. If I get a 300 amp programmable one, I am thinking that I might be able to get it run just fine with tweaking (little or alot). Any help or thoughts would be greatly appreciated. I am totally frustrated right now and wife is getting up set over money I am spending on this cart.