Power Fc Tacho Wiring

[scr33min']

Ok so I'm trying to wire up the stock tacho in a dr30 to a power fc. The power fc is a s13 sr20de+t so it has an sr20 wiring harness which is all wired up and working with the fj20 motor. So, looking at some ecu pinouts for the sr20 I found the rpm signal wire for the tacho, but theres no signal coming from it. I then tried to splice into the cas 180 sensor which has a signal but the tacho didn't work. Would anyone have any ideas on how I'm going to get this tacho to work? The power fc has rpm input as i have it shown on the hand controller, it's just annoying to have to constantly look at the tiny screen.Any help would be greatly appreciated

[BH_SLO32]

Ok so I'm trying to wire up the stock tacho in a dr30 to a power fc. The power fc is a s13 sr20de+t so it has an sr20 wiring harness which is all wired up and working with the fj20 motor. So, looking at some ecu pinouts for the sr20 I found the rpm signal wire for the tacho, but theres no signal coming from it. I then tried to splice into the cas 180 sensor which has a signal but the tacho didn't work. Would anyone have any ideas on how I'm going to get this tacho to work? The power fc has rpm input as i have it shown on the hand controller, it's just annoying to have to constantly look at the tiny screen.Any help would be greatly appreciated

The 90's nissan engine management systems (as found in the Silvias and skylines) typically control the tacho by simply earthing a powered supply FROM the tacho on the dash. The R31s and VL tachos operate somewhat in reverse in that they RECEIVE a signal from the ECU or distributor. Assuming the correct SR20 ECU tacho pin is connected to the correct wire from the tacho in the dash, you should be able to simply connect a 12V supply to the tacho wire via a resistor (from memory I have used a 10kOhm resistor). The resistor will limit the current draw and prevent damage to the ECU. This has worked successfully on the R31's and VL's and although I haven't worked on an R30 before I would expect the tacho to operate in the same manner as the R31.