My door ajar light won't go off!! If I open the rear passanger door or the tail gate it will stay on all day. Is this a fuse prob. or a latch prob? Please help...it makes the lights stay on until I drive forward fast enough and I can't see when I back up.

 

You probably have a door ajar sensor failure.
This was common in the 2000 Excursions (I had 2 of them)
and some of the late 90's F150/Expeditions as well.
The lock actuators are the next to go. )
They are a bit tricky to change as they are inside the doors.
Get the parts online and do them yourself if you can, Ford wanted $300 per door
and I got all of the lock actuators and door ajars for less than that
and replaced every one of them at one time after I did onzies on one truck
and it started to drive me nuts.
There are left and right actuators, but I can't remember which the rear is - L/R.
I think there is only one door ajar sensor but make sure before you order 5 of them.

I think I got mine at rockauto but not sure...

Justin.