my interior light has stopped working when i open or lock the car

Brian, June 2011

check the bulb is good
check the door switch contacts
check the light changeover switch position

wirecutterman, June 2011

Some cars have a three position switch (in series) - always on - always off - on and off according to the door opening.

There will be the light bulb itself - switches (in parallel) that sense the door opening and a fuse.

There may also be a timer circuit to delay the turning off.

These are the areas to pay attention to - there is a very remote possibility of a wiring fault - a poor connection perhaps.

Peccavi, June 2011