Rb25det Aftermarket Tach wiring

[Flatline1121]

So the tach output on my RB ecu is shot (looks like this one s13-rb25-tach-resistor-help-t560579.html) and i feel that money would be better spent on something besides a tach signal converter.

Rb25det s1. 97 S14 chassis that had zero body wiring when i got it. im surprised it ran.

Ive already read about the dakota digital converter, the MSD 8913, and such. the MSD would be my choice if i had to buy one because it connects to a coil + wire instead of just using the alt signal.

My question is, would it be possible to wire a tach off of the 1* or 120* wires off of the CAS?

In my searches the past few days, i read that the CAS should output 5v from this wire in a pulse just like the tach signal wire in pin #7. So assuming thats true, would it be possible to wire in a pull-up resistor through 12v to get a raw tach signal? Obviously i would be diode isolating this 12v source to prevent and back feeding to the sensor or the ecu.

Im pretty fresh to the RB and i dont want to mess anything up more than it already is.

[240z4u]

I had the same situation with my car. In the end it made more sense to get a fully functioning ECU.

[Flatline1121]

Yeah I imagined that would be best. But these arent too easy to find locally. I wound up finidng an MSD 8913 for 40 bucks so nabbed it.