just above the slide buttons, there is a single black switch that is marked only with "light" on/off. I just purchased this 2014 unit this weekend, love every feature, just attempting to identify what everything does. I don't find the general nature of the owners manual helpful as some things, such as an outline/overview of each function of this panel in detail is not to be found in the one I received with the unit. thanks for the assistance, many more questions/answers to come I hope.