Hey guys not sure if this is where this question goes, but if not please move it to the appropriate area.

I have a 2004 xb i have a neighbor who mentioned to me that the tailight is out... I know this might sound stupid but i never paid attention to the three tailights :?. Of the three lights which of them should be on at all times while the car is on? There is a middle light that is not on.

The break light works fine and is on at the moment, the reverse light comes on when i put the car in reverse.

Please help and sorry for the newbie question but couldnt find an answer..

 

There are 4 segments in the stock xB tail light assembly. From top to bottom they are:
1. Running light/brake light. Dual filament clear bulb behind red cover.
2. Turn signal/Hazard. Single filament amber bulb
3. Reflector, no bulb
4. Backup, single filament clear bulb.

None of them are on at all times, unless the lights are on. If your brake lights are on all the time, something's wrong.