Hey, my brother and I are rebuilding his 325i and have serious problems with the tachometer. It is stuck on 1k rpm. Its it stuck there wether the ECU is plugged in or not. Imediately, when the ignition is turned one step, it rises to 1k rpm. We've tried changing coding plugs, checked the batteries, changed the SI-board, reset the service LEDs, checked the black wire from clusterplug to earth, we've checked all fuses, and the ground connection wth the pedals looked okey. We are out of ideas on how to fix this. Also, the temperature gauge is at the fullest and the MPG is moving a centimeter, then stops. The car has no OBC.
Does anyone know to fix this?

