I recently took my car, A4 Avant in for its MOT and it failed on DIM lights. On checking I've only got 10.4 volts at the lights, both sides at rear and on the tailgate. Indicators and reversing light are OK. Any ideaS? 

Hello Fred,

The first port of call for such things is to check the wiring within the flexible section which runs from the body to the tailgate. Carefully peel back the corrugated rubber section - having pulled out the shaped rubber grommet from one end - and inspect each wire. They are prone to splitting due to this section being flexed every time the tailgate is opened, and eventually can stay together only by a couple of strands. 

Kind regards,

Gareth. 

Hi Fred did you manage to fix your low voltage lights only I have the same problem