THE CAR: a 1996 900SE, with 88,000 miles.
THE PROBLEM: after three years of starting reliably, including after a week left at an airport, during which time there was a foot of snow, in the current East Coast cold spell, the car refuses to start. My diagnosis: the battery needs to be replaced. After all, I've owned the car for three years, and the battery is the one that was in it when I bought the car. It's a Saab battery -- is it conceivable that it is the ORIGINAL battery? So I get a jump-start from my neighbor, and drive into work. The car then spends the day in an underground garage, but won't start in the evening. Get another jump-start from one of my colleagues, and then drive home.
THE MYSTERY: While driving home, the car -- which is an automatic -- won't change up into the appropriate gear. At about 50 mph it's running at 4,000 RPM, and when it finally does change up, it does so with a major jerk. I'm dismayed, thinking that not only do I need a new battery, but some kind of (possibly very expensive) unrelated transmission problem has developed. So, today (Saturday), I get another jump start from my neighbor, drive to the local NTB, and have them install a new battery. I anticipate that, when the car will start reliably, I'll address the transmission problem. But, when I pick up the car, the transmission problem HAS DISAPPEARED! The car runs smoothly, and shifts appropriately.
THE QUESTION; Why? Why would having a bad battery affect the transmission, and why would putting in a new battery fix the problem? Is this something that's peculiar to Saabs?