2003 Chevrolet Tracker

There is a door switch on four door models that could be the problem. The rear dome lamp is dependeant on every door switch on a 2 door and that would mean any of the door switches could be bad, but that should leave the front dome on, unless it is strictly the map lights up front and I am not reading the wiring diagram correctly.
I either case you have a bad door or dome switch. I attached the wiring diagram so you can trace them. I do not have the position of the switch on the door but you will be looking for a plunger type switch. When you pull it and un plug it the dome light should go off when you find the bad switch.