Electrics problems

After moving to France I had to change the positions of the rear fog lamp and reverse light.
I did this by simply switching the plastic covers and swapping the wires.
This worked beautifully for about a year, but mow the fog light doesn't work at all and the reverse light is benefiting from french employment law. (One week on then three weeks off.)
I don't even know where to start in debugging something like this. Anyone have any ideas?


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Also I have a similar problem to that other poor bugger in that when when my windscreen wipers are on and I do something else, eg. use brakes, indicate. The wipers will momentarily stop.
Any clues?

Defo an earth problem. You`ll need to trace them all and check.

Cool. How do I check them? Do I need one of those glowing screwdrivers?

Multimeter or one of these

[ame=http://www.amazon.co.uk/Sealey-Auto-Probe-Plus-6-24V/dp/B000R9Y35C]Sealey PPX Auto Probe Plus 6-24V: Amazon.co.uk: Garden & Outdoors[/ame]

or if you're lucky, just look for a chaffed wire as it passes through the chassis

Check if the live is ok - if not trace back.

If it is the chase the earth back to where it attaches to the chassis - after each connector )spray with wd40) check if they work again.

Let us know.................