3400 24x crank sensor voltage

[lars49]

Does anyone know what the amplitude of the voltage is out of the 24x crank sensor? I'm hooking up a VDO tach and using this signal/4 seems to be a good solution.

[bszopi]

Why not just use the tach output from the ICM?

[CNCguy]

The VDO tachs won't respond to the ICMs output. Since they are newer electronic gauges, it seems like they could use the signal but no one has had any luck doing so.

[Guest]

You probably need to modify the signal input of the tach.

I have a Dutsun 280Z tach, that would work fine with a dizzy ignition, but would not respond at all to the DIS ignition.

I had to bypass a resistor, that was in the input section of the tach itself.

I have another tach, that showed the same symptom, both in car and on my ECM test bench. I was able to get it working by using a pull up resistor. I don't recall the value, but somewhere around 1K to 1.5K ohm, IIRC, connected between the tach input and 12V.

[bszopi]

Interesting. Still learn something new every day!