I'm pretty sure that I read somewhere that the wiring on a Lag II is already on the car in the form of a connector block.
I'm afraid not
. I did my 2002 L2 myself, and watched (and supplied cups of tea) while the fitter did my 2005. In both cases, it's been a necessary to tap directly into the wiring at the rear of the lights as you would with most other cars.
Like many people, I'd heard that the L2 had multiplex wiring, so I invested in the official Renault loom (about 50 quid) first time around. This does give you a kind of 'plug and play' arrangement, though the whole thing is a bit 'Heath Robinson.' Basically, it has two plugs for each lamp cluster, and a little strip of circuit board to convert one of those plugs from female to male. You disconnect the existing plug and stick the new plug with the board into that, then stick the remaining new plug into the back of the light. There are no bypass relays in the official Renault loom - only the usual buzzer relay for the indicators. For that reason (and on the advice of the fitter) I didn't bother with bypass relays or the Renault loom this time round.
Do it yourself my friend .. all the holes are pre-drilled in the chassis and protected with rubber grommets ... its really easy to do(careful when putting in spacers as they can drop into box section of chassis). As for the wiring , just follow the instructions that comes with the kit , i had no problem ... alternativly i think renault do a connector block that you just plug in
Good advice. Just to add that you should invest in a torque wrench if you don't already have one, and torque every bolt to the setting shown in the fitting instructions. Don't just do them up tight. If you're going for a flange style bar, you'll find the torque settings on the flange bolts tend to be off the scale of most DIY wrenches, so you might want to take it round to your local independent mechanic and see if they'll torque them up for the price of a pint.
The 12N (road lighting) wiring on the ST should be a piece of cake, as none of the lamps are fitted to the boot lid. The 12S (battery and fridge supply if you're towing a caravan) is a lot trickier, and really needs to be run straight from the battery along the underside of the car and into the boot. This was the main reason why I opted to pay someone to do the job this time round. I was prepared to DIY the rest, but I wouldn't have had the use of a lift this time round, and I reckoned the 12S would be a nightmare on just axle stands. I watched the fitter do it, and he just confirmed my suspicions