My interior lights don't work on my VW sharan 2004

Check the fuses for the interior lights.

Glove box illumination should be on the same circuit as the courtesy lights...and they have constant power...so check the fuse box on the driver's side fuse panel, and look for the "Dome," or "Courtesy," fuse (usually 5-10amp)...check and replace. Now if the lighting is the only thing effected you should be able to overcome...however there is a courtesy/convenience computer (often overlooked) which can go bad causing all interior lights (incl. gauges) and sunroof/windows to fail. Just something to keep in mind. Let me know if you are able to ace this one!