E38750i1995 with low voltage faults

Hi, my750i 1995 (E38) suddenly felt like the power steering is off when driving close to stand still. On the road the blinking indicator lights would go off when driving above 30 mph. Also the computer would go off as well as the radio. The blinking indicator lights would start working when driving below 30mph again, not so the board computer or radio. After re-starting, the radio et cet would work again.
The dealer could find only low voltage faults. The only explanation was that after market accessories (TV, video) should not be used.
What is the underlaying problem? Anyone with similar experience?
Thanks. Dieter.

:rolleyes:Hi, I learned today from another 7 driver that he had a similar problem. The solution was to clean the contacts in the control box (LKA)next to the front fuse box.
I will give a shot tomorrow.