Courtesy lights stay on all the time even when car is off

The courtesy lights work on a relay/switch to turn the lights off 15 - 30 seconds when the doors are open then closed. If the relay is staying to cold then it cannot heat up to break the circuit to the courtesy lights. I would first try replacing the courtesy light relay and if that fails to solve the problem, the switch may be the faulty candidate.

check for loose dirty battery terminals /dirty loose earth points. This is an indication of incomplete electrical circuit

Is there perhaps a problem with the dome light switch on the lift gate? Close all the doors, open only the lift gate and find the switch on the lift gate frame (usually a rubber covered "bump") and press it in. You might have a loose wire shorting against the bodywork or the door is not depressing the switch properly.

I suggest you replace the daytime running light module.

that is the courtesy lights thing. it helps you see what your doing at night

Remove the IOD fuse and leave out overnight this will reset the BCM and probably resolve the diming light and the dome light issue, I had the same prob in my 2006 Grand Caravan.
Good Lock

some dimmer switches control the time the interior lights stay on and for how long

correction...the relay would be stuck in the closed position the energized position

the head light switch

I am not much of a mechanic any more ,but I do have some experince with electronics and for any circuit to operate battery has to flow to ground.Direct battery to ground will blow a fuse or melt your wiring if the fuse does not blow.If your parking lights stay on all the time then there is a complete path from battery to grd through the lights,and it sounds as though what ever is causing the problem on the parking lights is killing the path to your lamps relay.A wiring diagram may be available on the internt or library.Good luck.

tk46