This is a potential fire hazard or electrical short circuit in the headlights. The city/parking light is especially prone to this problem on the Golf 5, Jetta 5, Passat and other models.
Remove the lights on this Mk5 2009 GTI and found the wires almost shorting together due to the insulation being deteriorated. Only the length nearest to the bulb seems to be hardened and brittle. We taped up the affected length with head resistance insulating shield tape. Believe that the heat created by the bulb may be the cause of the deterioration.
Upgraded the City/Parking Light Bulb which is originally fitted with a T10 Halogen bulb to a CREE-5 bulb which is very bright and is error free.
|View when cap was removed.|
|The Grey Wire is 12 volts positive is already partially exposed|
A blue glass T10 halogen bulb was installed earlier.
|Tape the affected length of wire with heat insulating shield tapes.|
The CREE-5 LED bulb is used.
|The CREE-5 Bulb creates less heat but is very much brighter|
|The new CREE-5 Bulb in action !|
|Bright enough to be used as DRL bulbs on the GTI|