L200 Indicator/brake Alarm

Hmmm, my L200 has developed a new & Intermittent fault whereby there is a loud audible alarm from behind the dash when I apply the brake, the hazzards or the left hand indicator (but strangely not the right!). It does it for half an hour or so, then goes away, then a day or two later, it'll be back, same thing. The fact that it's the left hand indicator & the brake would indicate a problem of some sort with the left rear lighting unit, but wanted to know if anyone else had suffered anything similar before I go dismantling stuff!

Cheers

Damian