Battery Drain

[Big Mark]

Hi Everyone...I'm after a little help/advice.
Has anyone been suffering or suffered battery drain due to the audio system.

I'll explain my situation....If I leave fuse72 (30amp) connected the battery drains overnight however if you leave the fuse connected but disconnect the multi plug to the becker module it doesn't.

I've had the car to an Auto-Electrician and he said that when the car has gone into sleep mode there is still a drain coming from the purple/white lead in said multi plug but he has been unable to find why, he said that all components has been checked and the drain is not caused by them.
So due any of you nice people have any ideas yourselves what could be causing it.

Also I forgot to mention that the module has been refurbed. I have read on here somewhere that someone swapped the switched live from the rear heated seat relay with the permanent live of the audio relay do you think that this will make for a good solution to the problem or not.

Any feedback will be much appreciated so I can finally start listening to music.