Interior lights and dash lights do not work on my 2000 Jaguar S-type

Hey Parnell, chances are the fault could lie with the fuses or with the body control module, I don't have a lot of experience with this model Jag so start with the fuses, if memory serves, there are two fuse panels, one under the bonnet and the other above the drivers knees inside the car, check them electrically with a test probe, looking at them is not enough. Replace any that are blown. If they blow again, seek the help of a qualified professional. If the issue is with the body control module, dont mess with it, have it repaired by a qualified professional. Check the lights switch and the interior light switch as well, if they are both on the same control ( interior lights and dash lamp dimmer) check it to ensure it is switching correctly. You may find that the dash lights and the external parking lamps may not be working as they are connected in some models so go the fuses first. If all else fails, try your local library for a copy of the wiring diagram or search it out online, this will tell you what and where the lights are connected and how they are switched. You can then backtrack each circuit to locate the issue. Again, if it looks like the issue is in the body control module, dont mess with it, that technology needs very specialist equipment and training..