Hi, im trying to get an MOT for my MK-3,

The tester has failed it on the fact that when the indicator is flashing, it causes the head light to dim ever so slightly, i have tried re earthing all lights seperatly, and even turning the idle speed right up just for the MOT, but it has had no effect.

Can this be sorted out?

The head light on mine is 12V as are the indicators (they are both aftermarket, as the tester said that the standard head light had the incorrect pattern (not ec marked).

Is the tester just being too picky?

id say yes, my mk3 has an aftermarket headlight with a crack in it, and he passed it without a problem. the only thing he spend most of the time checking was the tyres.
check that the wiring to the headlight and indicator switch is ok
if there is a bad connection then you might have the problem you have.
Jon

wiring is fine, as it is all new, i replaced the switch gear at the same time as the lights.

check what wattage bulbs are in the indicators, they may be drawing too much current. reduce the wattage in one or both bulbs. try just replacing the rear bulbs for now and see how that does. they may flash a bit quicker but will be ok for the test.
Jon

Had a similar prob, with my old KDX ,butr has it happens it turned out to be a bit of a result as i went to an alternative garage and found a couple of great blokes who both have CRMs and trail ride [ Normandy Motorcycles] and INTERPRET the regulations more sympathetically.
Regards Mike

Can't you just remove the indicators?