2014 Tahoe headlights dim intermittently

[JBravo1977]

My 2014 Tahoe started having a problem with the (original factory) headlights dimming intermittently while driving at night. Both sides dim the same amount at the same times then brighten back up. This is on low beam and I'm not sure if it does it on high beam or not. Because both sides dim together, it leads me to believe that it's not the bulbs (but I wouldn't be surprised if one bad bulb could make both do that somehow.) More importantly, the battery and alternator were replaced several months ago and I'm not having any other electrical problems, so I would be surprised if the battery or alternator were the problem. My best guess is a loose wire, but I don't know how to begin to get in there and look for it. Any ideas would be appreciated. I need to keep the old girl on the road as long as possible, because I left my extra $70K in my other jeans, and because I have a medical issue with my spine that requires my driver's seat to have been modified, and this is the only vehicle I can drive.