Join Date: Dec 2005
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If the filament is slightly damaged or weak in a bulb it will intermittantly work/not work.The favorite trick with a bulb thats not working is to tap the light lense and it starts working.All thats happening is the filament is moving and temporarily making contact so it works.A bump in the road does exactly the same thing,so I suspect you have a faulty bulb which is working intermittantly.
Currently in Lagdti's garage:
2004 Saab 9-5 HOT Aero and a 2001 Audi A3 1.8 Turbo