Hi chaps, first post here so I hope I'm not treading on any toes...
I have a clean and excellent Mk.3 which has done 20,000 miles in the last year with no problems... except one.
In wet weather, when the side- or headlights are on, the left indicator occasionally becomes 'sticky'. It then produces a steady (not flashing) light and may continue to do so even with the indicator switch returned to the 'off' position. If so, the only way to 'clear' it is to switch the lights off.
My excellent, well-regarded local garage has had three goes at sorting it. Clearly there is a short between the indicator and main beam circuits somewhere that is sensitive to moisture, but it's pretty damned evasive.
I'd happily take it to a specialist if someone wanted to recommend one around Bristol, Eastleigh/Winchester, or Chichester. But I'd be even happier if someone said "That happened to me, too" and told me which wiring loom or junction box to check.
Best, Will
