Ok well i thought id print off the trouble shooting chart and try again. And this time i actually read it properly haha.

For some reason i thought i had 5 different colored wires. Had a bit of a brain lapse i guess... I only have 3 DIFFERENT colour wires.

Anyway everything checked out apart from the voltage across the regulator output and the battery terminals. They are supposed to be less than 0.20 volts.
On the positive it was 0.19 and the negative was 0.21, so pretty close but i wasnt happy so checked all the connections and cleaned and then ran another line from + & - on the reg/rec to the + & - on the battery respectivley.

And problem solved... no flickering no dimming. Guess its just crap wiring. Bad earths. That sort of thing.

Anyways cheers for everyones input.