I am new to this site, and it's great. I have a 2003 Expy. that has some wierd issues, you will be driving along everything fine then the interior lights come on,the door ajar light comes on and the annoying ding ding. all doors are firmly shut. It will even do this while parked in the drive-way with no one around it. My kids think it's haunted, do I call the Ghost Busters or can someone here help. I have tried to squirt WD-40 into the doors to wash stiff grease on switch pins, but no help.
Good chance a door ajar switch is bad. Which one? Start with the drivers or passenger front door since they get used the most. Take door panel off and get to the switch and clean it, test it. You may need to replace it. This might be a trial and error thing. Not sure if there is a way to figure out with a scan tool what door it is coming from. The switches are inside so spraying WD-40 is probably not going to help. If the switch is bad, that won't solve anything. Oh, you may want to use something different like a white lithium grease for lubricating the door latches. WD-40 is messy and doesn't lubricate well, it drips off and soon it will be dry and you will have to spray it again.