Rusty selector switch ( the one on the roof with the option Door-Off-On).
Faulty door switch ( it's located on the door jamb when you open the door you can see it near door lock latch on the car's frame), they are easy to open, open them have look a simple cleaning does the trick most of the time.
Hope this helps and please rate the answer if you found it useful, thanks!
Answers & Comments
The door switch is jammed or a wire is bared and grounding.
Look for a pin switch protruding from the door frame. It should push in and out easily.
If stuck pull out gently with pliers. Push in and out a few times to free it up.
No go?
Remove the switch. Make sure the positive wire is connected. The ground is the screw that holds the switch in place. Check for correct operation.
If faulty replace. It is usually not faulty as it is a simple thing. You can often fix it.
Adrian
It could be any of these:- Burnt out light bulb.
- Rusty selector switch ( the one on the roof with the option Door-Off-On).
- Faulty door switch ( it's located on the door jamb when you open the door you can see it near door lock latch on the car's frame), they are easy to open, open them have look a simple cleaning does the trick most of the time.
Hope this helps and please rate the answer if you found it useful, thanks!