Hi to all! My friend got an airstream classic 250 from 1992 and the speedometer gives us problems. It actually seems to work, but quite often it jumps to higher readėngs to stay thee for a while. When checking eiring I found thar there are four cables connected. Only the red ine goes to pink/blck means ignition, the rest (white,yellow and black) is connected to ground. How that? The speedometer should be fed from the TCM, right? Why does he work at all? Anyone with some knowledge about these VDo speedometer plese enlighten us!