Thanks for your reply. I have read a lot about wiring harness and bad contacts and tried to connect and disconnect and twist to find anything that could affect this mode, but so far nothing that gives me a clue.
My car has only ASD, not ASR, and no lamps are coming on or anything in the memory that can indicate what has occured. So I am leaving the alternator out of the picture for the time being.
The major problem is that just a few degrees lower temperature around the engine and the problem disappears again!?
What can be so sensitive and remaining coming back for the third summer?
It seems like a bad connection and I have read about the crank position sensor causing similar problems. Can it be so sensitive to surrounding temperatures as a couple of degrees? And if so, what to look for?