dmingo777

I've encountered a very strange issue. I replaced my convenience battery several months ago and probably need to replace the starter battery, but the starter battery still has some life. However, on days when I open and close the vario roof, the starter battery has a difficult time starting the car. On days that I don't open the roof, the car starts on the first crank.

The roof electronics functions are tied to the convenience battery, no? Why is there a direct correlation between the roof operation and the starter battery? Paint me confused.