Since I had a little dent taken out just below the number plate, one of my number plate lights has been intermittent. Often showing up as a fault on the dash, and sure enough it is not lit. A tap on the unit brings it back on.....but it keeps failing.

I have had the unit out and tapped, shaken and generally bounced it around...and it stays lit with no spluttering or anything. As there are no grounding issues (the light has two wires) and all seems secure when inspected, what can be causing such erratic behaviour?

 

MkIII 1.2 TSi SE Hatch

A wire damaged during the dent repair, the ground wire not well grounded due to corrosion or paint or loose bolt?

Thanks for responding.  Yes, I am starting to look towards the wiring. It doesn't seem to have been disturbed but a closer look required, I think.

Did they use any heat when fixing the dent? Maybe the clips that the bulb plugs into have relaxed?

Thanks PetrolDave for your help.

Bit embarrassing, but it was solved by fitting a new bulb!    In my (old) head I thought it couldn't be that as the bulb worked fine when I removed the fitting, as described above.  I guess it's these sensitive ECUs.....detecting a small change voltage as the build starts to fail.  Or something like that.

 

(Replacing the rear wipe motor was a breeze by comparison!)