Many thanks for your helpful reply T911 - and I wonder whether you (or other forum contributors) can shed some further light on the ongoing functionality of my 993's cigarette lighter!
I have now established that (when the car's lights are on and the body of the lighter is removed) there is indeed a light within the empty socket. So far, so good! I find though that the lighter unit - when pushed in - now doesn't stay in to heat the element, although when I physically hold the lighter unit in, the element does heat up.
I use an Porsche-branded CTEK conditioner, and I seem to recall the previous owner of the car saying something about the cigarette lighter socket being 'adapted' to allow for the regular insertion of the CTEK plug. Might this be the root cause of this latest issue?
As a non-smoker, I am not personally inconvenienced as to whether the cigarette lighter works or not, but I would like everything to do with the car to operate as originally intended, so I remain keen to get to the bottom of this switchgear 'niggle'.
Further thoughts/help would be welcomed.
Thanks, John