s13 sr20 swap tachometer wiring HELP!

[fear@loathing]

Swaped an s13 sr20det into my s13 240sx. initialy tach and speedo did not work... (i have a cluster from a 180sx) fixed speedo traced yellow/red tach signal wire... connects to ecu and cluster... traced into engine bay and ends their. i cannot find another yellow/red stripe wire to connect it to (TORE APART MY ENTIRE HARNESS!). The only conclution i can come up with is that it connects to another color wire and i have spent countless hours searching for info on it but all i can find is ecu pinouts PLEASE SOME1 HELP ME!

[PyR0NiAk]

You ever get this fixed?? I'm getting ready to start on my swap and trying to read up on all the problems people face...