Golf GTI relays

I have a mk2 1988 16v Golf GTI, could you possibly tell me exactly what each relay does on the fuse box (no.s corresponding to the items that they control) as I am having some electrical problems which I believe lead to the relays, if this is not possible could you please give me some idea as why my dashbaord lights, trip computer and dials do not work when the light switch is engaged? thakyou hope to hear from you soon.