Well finally,
After being unable to remove my alti off the defender ( 10mm bolt is tight on the bottom fixing, Doh yet another job, LOL) .
I decided to start swapping bits with the old broken alti, So I swapped the regulator. put it back in the disco and what do you know, I know Have an alti the gives voltage as soon as the engine fires up.
Thanks for all the help.
Cheers
neil