Rahu and Ketu as Separating Factors
Ketu shows where we are karmically strong. Rahu shows where we are karmically weak. The placement of Ketu shows a power developed from many past lifetimes. While we may still not get satisfaction from those things Ketu is influencing, he still gives a strong karmic foundation in regards to what area of life he is influencing.
If Ketu is influencing your Sun, it may give extremely strong leadership skills or a regal bearing, but you would still have difficulty finding enjoyment through that. Remember, the nodes show areas of life we still need to work on and develop. Ketu requires balanced development and detachment from the innate strengths he is influencing. Rahu requires that you explore and learn how to develop the area of life Rahu is influencing.
Rahu shows our karmic weakness, where we lack understanding. Rahu causes efforts to fall through and fail. This is because of difficulty knowing how to complete the job required. One can start with good and intense intention with Rahu, but then area of life starts to fall apart because one does not know how to complete the work required, usually because of lack of experience. Remember, Rahu deals with confusion. The separation occurs simply because of failure. With the other separating factors (Sun, Saturn, and 12th lord from the house in question), separation occurs because of something being taken away or sacrificed or exhausted. With Rahu, things seem like they are being taken away, when really one just fails to execute the plan properly due to confusion and lack of experience.
For an in-depth understanding of how to master Rahu and Ketu, please see the mp3 audio course taught by Ernst Wilhelm. Click on this link for more details.