My rear driver side brake lamp failed here a few days ago on my 99 explorer xlt. as normally when a light fails, i go down to the local wal-mart and grab another. Only this time.. it still would not illuminate. I took the lamp out and connected it to the passenger side brake lamp and it worked fine. I can't think of why it just wouldn't work... There is no corrosion in the plug, wiring is clean at the connector, and all fuses are good. Any help would be appreciated. Thanks!