Interior lights flicker on just briefly when doors are opened then go out.Replaced door switches and light harness but still have problem..any ideas?

Open each door (one at a time) with the car running and parked.
Look for the small contact switch that tells the car the door is open/shut.
See image for location.
Press that switch in firmly and watch the dash to see if the light comes on while you are pressing.
This will tell you which one of the switches is bad.

the door switch has a single wire to it ,when the door is closed the switch moves back and stops the wire touching earth to switch the light off , when door is opened the switch moves forward and allows the wire to contact metal earth of the switch hence closing the circuit to bring lights on , remove switch and clean with a solvent the switch must be bolted to the body to create earth when testing

check grounds sounds like plunger switch at door is going bad.

If I am remembering correctly, the switch is part of the latch. Each door has its own switch to turn on the interior light, and it sounds like the switch in the driver's door latch is either stuck or junk. If it has to be replaced it is very simple to remove for those that know how, but a nightmare for those that don't. The exterior handle has to be removed to release the pull-cord to the latch, interior trim panel and vapor barrier has to come off. Electrical harness, lock rod, interior handle rod, all have to be removed. Now the latch. Then it all has to go back together, and most importantly, it all has to work. I'm not saying it's not possible. I'm saying that it can ruin your day and your wallet if something goes wrong.

Have you recently done any work in the doors? It sounds like a short or connection issue with your door lock harness inside your door.

1. If you have the light switch in the wrong mode the lights will not operate when you open the door.

2. If the interior lights do not operate at all (ie you cannot switch them on and off manually)then you need to check the fuse for the interior lights.

3. When set to the correct mode, the interior lights will operate from a door operated switch so if the switch has failed the lights will either stay on or not operate at all when you open and close the door. Eventually these door switches fail with repeated use and need to be replaced. (Consider how many times the small door switch has been operated since 1996).

Door switch operation when drivers door pin switch open position; poor ground circuit control. Try wiggle testing pin switch. Harness is routed from door switch along floor board rocker sill.

this problem is caused by a tiny micro switch that is attached to the door latch inside the doors, the stick and give this false warning, have replaced dozens of them, it is called the "door ajar" switch oddly enough :)

Sounds like you require a new interior light switch on the passenger door. Find this little push button switch and give it a few flicks and taps with your finger and see if the light at least flickers. You could open the drivers door and fiddle about until you determine which and where is the switch.

is yiur batery in your key ok?