So i have a dewalt 20v max impact driver, the one with the 3 speed selector switch. it has this very weird thing where sometimes #1 which is supposed to be slow speed, will randomly act as high speed. sometimes #3 high speed it will act like its half speed and then the next trigger pull will be full speed again. weird… #2 seems to work like it should. it must be something to do with the electronics that control the brushless motor.