No Tach after Power FC D-Jetro Install

[Luvs2slide]

Car is a 92 180sx w/ s13 redtop So put in a PFC D jetro and now my tachometer stopped working. I only cut the necessary wires needed for the IAT sensor (pin 21 & 26).

I originally had the stock ecu (# 62) and everything worked perfectly before the PFC install. The rest of my cluster works fine with no issues other than the tach..however, I have not been able to drive the car yet so can't confirm is speedo works.

Anyone have any ideas?

[Luvs2slide]

forgot to add that its a used PFC and for all I know worked in the previous car.

Is it possible that the pins may have been switched somehow?

Is there a specific function to turn the rpm on/off?