Door ajar and dome light stays on

The door switch on a B3000 is actuallt in the door latch assembly, so in order to get it out you would have to remove the door panel to get at it.

Once there you will find a wiring connector that has to be removed and then you will have to rotate the switch one way or the other to remove it. YOu might be able to clean it so it works, but probably not.

Cosmo. Mazda Tech