Got a '99 Explorer XLT. As soon as you start it there is a chime. Its different than the seat belt chime, more like the door open chime i guess. But when the door is open, the door ajar light comes on, and shuts off when the door is closed. It beeps 5 times every 5 seconds for about a minute, then it will quit for approx 20-30 minutes and do it again, its really annoying and i do not know what it could be, any ideas??