Headlight flickers on and off on 07 Boxster S

[Idiott]

Going down the highway my left headlight flickers off and on.  Must be a loose ground or a loose bulb.  Where is the ground for the headlight?

[vza]

Can be a lot of things. On my '99 I thought it was the bulb, swapped one out still had the flickering problem, then swapped the starter(for halogens) still had the problem. Then I opened up the casing where you replace the bulbs and took a closer look. Almost all the wiring insulation had cracked off the wires leaving bare metal to short out intermittently. I had to rewire the headlight assembly. Good luck. V  PS Could also be the light switch .....replaced that as well....was trashed and broken to little bits on the insde.