citroen berlingo rear tail-light and rear brake light?

my rear tail-light and rear brake light are not working. bulb and fuse seem ok. what else is there to check?
bloom, February 2009


done
the contacts fail on the units,replace them with new,ive tried cleaning and re bending them sometimes it works,but not for long! or try second hand

tony citroen, October 2012
link Click here to see other fixes for Citroen.