BMW E30 trackday car rev counter

[Bryan The Pilot]

Hello
I am rebuilding a trackday E3O which had a M52B28 conversion , I had to dismantle most of the wiring as the car had no dashboard at all just a alloy switch panel and a aftermarket RMD rev counter which worked fine , of course after getting everything else working again in the replacement dash I cannot get the rev taco to work , I have scoured the net but no luck , I did see one post that you take the signal off a "blue " wire in the ECU but mine has no solid blue ?? , the Wiring instructions that I got off the web are here
https://www.caigauge.com/documents//pdfs/pil019-36...
Perhaps someone will be kind enough to advise me further ??
thanks in advance
Bryan

[ian332isport]

On the M52 engine loom, there should be a large 25 pin connector that effectively plugs the engine harness into the car harness. Pin 20 of this connector should be the tacho signal. Look for a fairly thin black wire.