I've been testing an 86 M635. The power windows and the sunroof work, but usually it takes pushing them a few times before any movement. The computer is so dim that you have to put your face on it to read it. The owner had claimed that there are no electrical problems other than that "the power window switch needs a new wiring harness, approx. $15". He claims the computer bulb just needs to be replaced. I'm skeptical, but no electrician. I haven't noticed any other electrical problems other than a quick left blinker, which I assume is a bulb replacement problem. Any thoughts? Do you suspect these are small, independent problems or indicative of a lurking monster?