Some of these electrical demons require more than cursing, head scratching, google searching and forum posting to be appeased. Have you tried sacrificing a goat to the volcano gods during a blue moon? I wish I had a solution for you but I have to say I am truly thankful it’s not my car! One faulty electrical connection or integrated circuit is all it takes to cause a problem like this and it can be nearly impossible to find and fix without understanding the entire system. I wish you luck!