E34 ECU Grounding point

[soap1551]

Is the ECU grounding point on the firewall next to the ECU box? Asking because i have an erratic tachometer and i already have tried another instrument cluster that was 100% working and it did the same thing. I suspect it has some kind of grounding problem.

[shogun]

do you mean RPM gauge or the speedometer? In case the speedometer is erratic, see here http://www.bmwe34.net/E34main/Mainte...eed_sensor.htm
all grounding points are shown in the ETM's by built year https://shark.armchair.mb.ca/~dave/BMW/e34/ Please add to your profile the built year and month