Headlights

Hi Guys, I have a 205 1.1 Style and on the way home the other night I switched from main beam to dip on the headlights only to find a faint glow instead of the usual light. Managed to get as far as my local mechanic who had a look at it yesterday.He has managed to get dip working by removing the resistor in the circuit (odd set up that allows 1/6 power to the headlights according to Haynes) but he suspects a fault on the fuse board with the feed to the dim/dip switch. The weird thing is I now have no power to the front screen washers which I am pretty sure is on a separate circuit. All fuses seem to check out. Questions are. Which relay is the Dim /Dip and what else should I be checking? Any other ideas ? Thanks Morris