I have a 2013 XJL 5.0 and am now on a DIY kick, having just done a water pump replacement.

For the last few months, I have noticed that the right headlight spontaneously turns off. Sometimes shutting down the car and starting it up again gets the light to work. This problem is intermittent.
i still have the original bulbs, but my car only has 46k miles. The bulbs are still bright (to me), and when on, they look to have the same brightness.

Is this likely an electrical issue or a bad bulb?

Thanks!

 

Not sure but it could be bad wiring or grounding issues. I had this problem on another car and cleaning the grounding fixed it for me

 

Thanks!

Can you give a little more info on where and how you cleaned the grounding? If I need to access the headlamp unit to do it, I may just replace the bulbs anyway.

 

I did this for another car (not a Jaguar) but if you look at the diagram it looks like it's here (G1D131 or G1D129)