Just fitted new regulator not charging PLEASE HELP

[11gothevt11]

I fitted new regulator charging at 14.2 volts at 2500 rpm with battery light off but After 10 minutes of new regulator fitted drop to 11.7 volts at 2500 rpms with battery light on
Befor i fitted regulator i cleaned .sandpaper.all contact points on battery terimals and alternator
cleaned all earths i could find in engine bay...But couldn't find main earth on block
But i got a set of jumper leads put onto neg terminal with it off battery until i found got earth
So reconnected with jumper leads on battery and earth on jumpers to see if i have a earth problem
Made no differance


With new regulater all leads were showing similar to battery
And brushes showing 0.6 volts lower than battery

Engine off at battery 11.7v
But now at idle drop to 11.2 v
all points including brushes were about the same


But what is weird i put old regulator
Battery and other leads around the same but
Brushes were only showing 1.55 v and 3.2 v
So is this a way to tell old regulator is stuffed????????

But what about new regulator its not charging and theres power to the cables...
So what do i need to do to make 100% sure my alternator?????????
I am out of ideas
Please help
So

[accentstencil]

The best thing to do is take it to an auto electrician. The usually don't charge much just to diagnose a problem, sometimes they won't charge you at all if it doesn't take long.