Rb20det swap to ka24de dash 10k resistor not working...

[240sxRAOR]

I have two wires one from ecu the other goes to Tach. Both are yellow and red with silver wires. I hook them togather and get a signal at the tach but its wrong by 1.5x. So I take 12+ v wire and atach a 10k resistor and hook it to where my tach wires are spliced and nothing changes. This is exactly how people have described it and it doesnt work. If anyone has wiring diagram of how it should look or why might not work on mine, it would be much apreciated. I dont even understand how its supposed to change it and its pissing me off.

[240sxRAOR]

If you guys can tell me how to wire it correct I dont mind uploading an understandable wiring diagram instead of the bits and peices about this topic.