I call it a side light check the other side of the car that is working
is the side light and brake light in the SAME small space if YES you have a 2 element bulb called a stop&tail 12v/5w/21w change the bulb as the thin element wire WILL probably be broken .
TO TEST BULB 1 battery charger 12v, hold the neg clip on the body of the bulb touch any 1 of the 2 connections on the bottom of the bulb,(bulb MUST light) change to other bottom connection (bulb MUST light)(WARNING) do not let charger clips touch together as they will BLOW charger panel fuse If on refitting to car no light suspect fuse blown or bad EARTH connection ,or poor power connection
wirecutterman
January 2008