08-12-2012, 09:18 PM
Two filaments in one bulb, one for brake lights other for sidelights. Hold the bulb by metal bit and look at glass bit, flick the bulb, does one of the filaments vibrate or appear loose, if so blown bulb. Been around years and know as stop and tail light bulbs, beware of offset locating pins when refitting in holder...
Berlingo Multispace 2.0HDI '54 reg Mediterranean Blue