I'll keep a very long story reasonably short. After all of the above, I spent an afternoon looking for faulty grounds in the various wiring harnesses, I found half a dozen corroded wires in the one below the battery. the repair cost my about $5 and 6 hours, but the fix has been long term for ~3 months so far. Hope this helps.

 

The problem with my Chrysler was solved last year!

The solution was to replace the main fuzebox (is that what it's called in english?). Maybe You should look into that on your car.