Haha... i suck... such a rookie misstake... cleared out the cabel so i started comparing the two sides, cabels - same resistance, fuse ok, holder nice, bulbs looks ok. So i laid the bulbholders beside one another and started checking the resistance on the pins... and there was a difference. It dawned on me that i hadnt checked the resistance of the bulbs and the one with dual filiments was broken, but looked ok. Well... this i will remember.