Agent240sx

Can anyone help me?

Bought a car with a non working tach, swapped the tach and still no rpms.

Decided to buy a Pivot RCX which is pretty much a digital tach and shift light.



Went to install it which requires me to tap into the ECU tach signal output wire. My ECU is an "WE" s14 blacktop automatic ECU (car is manual). The pinout is below:



I go look at my ECU harness plug and realize there nothing attached to pin #7... UGH! no wires, was it de-pinned? any reason for this?

My question is can I just add a pin and attach the aftermarket Pivot tach wire into #7 to get the signal?

Thanks in advance!