My headlight shave developed a temperamental fault. When I turn on my head lights the full beam light on the dash glows faintly - not fully lit (as pictured).

When this happens the drivers side light itself is dim. It doesn't do it all the time but becoming more regular. It feels very much like an earth wiring fault. But wondered if anyone could point me in the direction of connections I should check/clean?
Thanks.

 

With it getting darker I decided to investigate this properly. Not a complex fault but for reference...
Discovered very quickly that the connector for the bulb had a bad connection and had melted. Will need to replace the connector but for now I cleaned up all the connections and re-assembled. Also cleaned the nearby earth point on the wing. Now lights work as they should and I shouldn't have been so lazy and had a better look first time around!

 

Good spot, and yes that would make sense with the glow.

Remember, earthing faults are a common ground throughout the vehicle, i.e. only one path back to negative on battery.

In your case you were getting a cross-connection between normal side/parking lights and main beam, so using that theory you look at where/how those two circuits could be crossed/connected in some minor way (not able to pass the large current required to light them fully, but enough for a small indicator bulb in the dash to glow). Water ingress is another common one that causes that (Good example are brake lights and side lights coming on at the same time due to a cross in the bulbs positive terminals due to water) as well as the melting you've found.

I've not seen a melted connector like that on these though, were the bulbs the correct rating, etc?

Glad you spotted it, and easy fix :-)

 

Glad you found it , it common the ground under the battery tray gets corroded also look out for wire fail "broken wire " there the harness route from the wing accross to the transmission.