M30 rev counter, eco not working and have swapped the wires

[Tims07]

Donor was E34 '88 3.5 Se

The loom plugs straight in, and the windows and heater work straight away, with doors closed or open.

However rev and swing thing do not, I have done the swap of pins 3 and 8, but no difference.

Any clues chaps?

[zaust]

Have you also put a live into pin 15 from the Starter motor ?.

[Tims07]

No, pin 15 on the M30 or E30 side? That is the Green and Black one is it not. Why from the starter, is that for a perminant live, in which case easier to come from the battery, or a switch live, or a pulsating live, if that makes sense

[zaust]

It should be on the e30 side. Will not always be green an black, but it will be pin 15. And iirc there is a input at the diag pug too.