Hi. My drivers side day running lights have become dull and can't find a fault. Any suggestions 

 

did you scan it for errors? these are not easy to diagnose, might as simple as wiring, but difficult to track where exactly

If you can, find another headlamp and unplug your offside/drivers headlamp and plug the wiring into the "spare" unit. If the fault persists, it's not the headlamp, if the DRL comes up bright on the spare unit then it's the light unit.

However, you may find if the spare is bright, the original might "miraculously" become bright - this points to corroded/dirty connections within the plugs.

8 hours ago, BiK3rZ said:

did you scan it for errors? these are not easy to diagnose, might as simple as wiring, but difficult to track where exactly

Thanks will get ot checked