Tim,
I've looked at my 1982 wiring charts, and it's showing relays for
main beams but not for dipped.
I installed 4 relays near the 4 lamps, and powered them from,
indirectly, the black/white permanent positive lines from each side of
the fuse/relay box.
(At the time, I hadn't realised the mains already had a relay, no matter.)
Nigel