Please do me a favor. I am newbie here and car.
A couple of weeks ago, I got rear light warning signal on dashboard, and found passenger side brake light was out. I replaced the bulb immediately without doubting anything else, but it still didn't work. All other rear lights work well including tail lights and directional lights. Driver side brake light works well, too. Only passenger side brake light has problem.
I read some here, and tried to clean the socket, and replace bulb several times, but didn't work. I also checked wires from trunk hinge area to the light, but couldn't see any breakage.
At this time, I don't know what the problem is, and what I can try to do.

 

Find someone with a volt-ohm meter. Test the socket terminal for 12V when brakes are on (typically the 12V wire would be Green with some kind colored stripe). And the ground wire terminal for continuity to ground (White/Black wire).

 

you can do this easily, its so easy to find someone with volt-ohm meter, please tell us the result after trying this one out,

 

I will try the volt-ohm meter.