I've a 88 735i, and already replaced the "printed circuit board" 2 years ago. The replacement fixed the haywire guage issue and the Odo looses memory issue. Now, after a long stint in the garage, my fuel, temp, and tacho guages are screwey. The fuel and temp go to 1/5th of full scale and never move. The OBC knows the fuel level because the range seems to work. The temp is ???. The Tacho doesn't read anything. What could be wrong? Any help would be greatly appreciated.