I have a 2008 LR2 with the Xenon head lamps. The passenger light would intermittently turn off. I replaced the bulbs thinking they were fading. Now the same passenger light only stays on for about 5 minutes and then shuts off. I restart the vehicle and it comes back on again. I noticed when I start the car the passenger light flickers before coming on full strength. Could this be the ballast failing?

 

I don't have any direct experience with this problem, but it sounds like the ballast. If you could switch the ballasts between the left and right side headlamps, that would be a confirming test. But I don't know how difficult that switch would be.

 

The LR2 ballasts are somewhat suspect. I fully agree with that as the diag.

Not too bad to swap from side to side, headlight assemblies need to come out, and it mounts to the bottom of the assembly.