Tach hook-up problem

[cschoen]

Gentlemen,
Maybe someone here will know the answer to this question? I am in process of hooking up a new 5 inch autometer tach and having some problems. It is a 04 LS1 GTO engine in a 94 S10 truck. I am hooked to the PCM terminal C10 and cut the blue loop on the tach. No Joy. Rechecked wire to computer with a ohm meter checks good. Re-check power and ground to tach. Checked good. Can you check the tach output from the computer? If so how? I am told the LS1 PCM tach output is a 4 cyl 2 pulse setup. Reason to cut the blue loop on the tach. Any suggestions?
Thanks,
Scott

[Cutlass]

All I can tell you is that tach signal is on terminal 10 on the PCM connector 2 (the green connector.) Terminal 10 is a brown wire. This info is for a 2004 GTO