Chev has a couple lights that are on during the day when you are driving. When you take the truck out of drive they turn off. Well one of them is out but the only way to verify that is to have your truck in drive and running I just want to be sure that the replacement bulb works before I button that mess all back up. I determined I had one out because the image off the car in front of me. Yeah ok I can go get another person but surely there is a way to turn those light on.