Sorry , i don't speak German.
I'd like to know how works the auxilary battery charging on my JC 309d from 1985 ? Because my battery does not charge when i'm on the road.
I have a converter 220 to 12 volt that charges the auxilary battery when i am stopped and connected to 220v. ( under the last seats )

But i don't know where is the stuff that charges both motor battery and auxilarybattery during the road, then separate them when i'm stopped.
Can some one tell me where is this stuff (because mine seams to be broken )
thank you,
bye