Mine did that, it would go on and off. Email Bruno, he will give you some suggestions for testing. My problem ended up being the connector in my fuse block that I powered the bruno box with. The connector wasn't snapped into the fuse block very well apparently, so it was sliding out the bottom of the fuse block. The tension and other wires wouldn't let it come out all the way, so it mainly was making contact and working fine. Every once in a while it would go off. Of course I started at the other end with my meter taking harnesses apart to try to find where the break was. If I would have started at the fuse, I would have found it in 10 seconds. Just had to take the fuse box off and snap the connector all the way back in from underneath, and has worked perfectly since. My problem was nothing to do with his controller. I bet if you open his box, there probably is only a few dollars worth of components in there that you could resolder to try. Maybe the Potentiometer went bad, did you test that? If you open the box, please post some pictures of it here.