Ah thank you , now i understand it.
Indeed i thought active render layers are disabled by default instead of enabled.
So the whole process went wrong.
Now i have a perfect result.
Stuped i did not notice that i inverted the process.
As I understood now ,Korman actually uses the same Uv handling process as i did manually before.
Thats why i assume that Ao is not included in this process either.
As far i know a full render does not do that.
I think you have to do nearly the same process twice.
1 time for the lightmap and 1 time for the ao.
Use the same uv map for both results on a different image.
Then multiply or add both images with each other.
Adding can become to dark sometimes.
(Manually i subtracted a flat grey layer again to fall into the correct greytones)
Then finally apply the combined image to the object(s)
In my experience Ao is as important as shadows , it gives more depth to objects.