Sounds like maybe a bad ground??? If the fuses are fine, you may need to do some testing on the wires to see if any of them are shorted out... or to see if one of the grounds is bad. I have heard rumors that bad grounds in cars can cause weird stuff like this (tries to ground itself thru other lights instead).
Definitely check the grounds. If you have had the infamous trunk leak, you could have one or more high resistance grounds due to corrosion. Check each one of them to see if they are clean and the wire itself isn't broken.
I know this may be hard to believe but a bad buld can also cause a short like the problem you are describing. By bad bulb I mean a bulb that should have burned out but due to a very strong filiment it is shorting out inside the bulb. I simply check the bulbs one at a time by replacing an old one with a new one and rechecking the problem Hope this helps you out. Don
I just encounter same problem on my 2000 bonne. No interior lights, no door locks work, Trunk will not open except for key and Fuel door does not unlock or lock except manual release. These all occured at once, With no mods done to car. I checked all fuses both Boxes none blown.