Aftermarket gauges need wiring help

[bushido8420]

Ok soo to start i bought an aftermarket I had to direct wire because the while some of te connectors worked they were not working the right things. Do example high beams turned on indicator and left signal made thw neutral light flash. But I have all that sorted but can't seem to get the tach to work any help would be greatly appreciated also I have the wiring diagram and it just looks like a jumbled mess to me hard to make sense of it

[92xjunker]

Tach signal comes from the ignition box.

[bushido8420]

Yeah I hooked the old one back up direct and it works but this aftermarket one won't