Many thanks Mlw, The 552 relay is indeed the flasher relay. Luckily I have a friend who is up to speed with this sort of stuff. I had emailled him a copy of the wiring diagram (I hope that isn't against any rules) and he asked me to see if the brake lights worked without turning the IGN key on. Well they didn't and after a phone call I was asked to check the fuses, as luck would have it the 2nd fuse I checked was blown. I replaced it and the flashers & brake lights now work. Unfortunately having vary-focal specs its difficult to read the printing on the fuse box but it was indeed the stp/haz fuse that had blown.
The last bit is to find a dodgy earth/ground at the front which hadn't shown itself before, as now when I use the turn indicators the correct one flashes without going out completely but the other lights dimly where it shouldn't light at all.
Mlw, If I can ever help you , I used to have a '74 D19 Brave on a M400 chassis (I think!) That was 9 years ago but I'm still in touch with the guy I sold it to.
Thanks Ian...
