Thanks Gary,

I couldn't remember the website where I had seen the code breakdown. So now that I have looked it up I find that the car originally had an M40 and I have an M41 or M410 (I will have to drag it out to look). This means that I will still have to sort out the weird relay that says overdive on it bolted to the firewall and why the reverse lights are running through such a big relay - back to the wiring diagrams!

edit - so apparently the non-OD cars still got the OD relay and the reverse lights do still run through it - of course I don't know what is further down the black wire that runs down to the tranny. Something is obviously grounding somewhere. I have just disconnected the relay for now (which means I do not have a horn either now but it will have to wait until after my exam.

Thanks for the assistance,
Aaron