2003 frontier diesel 2.5AX tach wire

Good day guy and gals, I have a 2003 nissan frontier 2.5 diesel that i'm trying to locate the tach wire to install a viper 791xv. the vehicle came with a viper 350 and i'm switching to a 791xv. i looked at the colour codes for the frontier but it's different from what i have. only the starter wire is the same . I know that countries like Malaysia and south africa have theses diesel vehicles. I removed the ECM and the harness and probed every wire coming out of there and only found one that reacts to ac voltage but it's around 6.6v and only changes about .7v when you step on the accelerator. the starter doest crank when trying to remote start and the shutdown diagnostic reports no or low rpm which is the tach wire not being right. i have the ign. wires correct because the turbo mode keeps the vehicle running and shutsdown correctly even though i'm using that 6.6v wire. can someone out there with a diesel frontier tell me which is the correct tach wire or how to locate it. i really don't want to go behind the instrument cluster since it is hell to get at the back there. Another question , if i have to use voltage sense, do i need to connect the tach wire? which wire from the alarm module monitors for voltage if i use the voltage sense instead of tach? thanks"I'm So Loud It Hertz"

Tach is a Light Blue at top on ENGINE or this is work perfect CAN-SL from CrimeStopper. Give the tach via DATABUS (OBD2 connector).

Hey , i don't follow what you mean by: top on engine. is this a connector from the engine bay area ?"I'm So Loud It Hertz"

Heres the simple answer use voltage sense then you dont need tach wire.Next if you feel you need to use te tach wire then use a directed tac signal generator,you dealer that sold you the 791,should have these in stock.Problem solvedJamaica home of the worlds fastest man.