I just started having the same issues with my 2015 Tahoe. Loss of cruise control, dash and radio lights flicker for a second, headlights also flicker a lil when i press the brakes. Use the turn signal to switch lanes and the cruise control cuts off. Has anyone found a solution to the problem? Battery cables are good and tight. Alternator is about a year old. Not sure how old the battery is but my dash shows its a 14v when the car is running although the voltage did drop a lil while i was driving but that was just for about 2-3 seconds.