What exactly does the tach use for a signal? Does anyone run an aftermarket tach? How/ what kind of signal did you use. And what model number tach did you use
shoot me a pm on the tach. also why would mine read so off?Pin #49 on the PCM is from the CPS to the PCM, carrying the raw pulses from the tonewheel on the cam gear. Pin #50 is as Smokyred mentioned, it runs from the PCM up to the instrument cluster and directly drives the tachometer. I haven't looked at the signal on pin #50, but it is probably generating a similar waveform to what a gasser gets for its tach.
I have a tach with shift light and recall in my truck, running directly off of the sensor wire on pin #49. I wanted to use the raw data from the sensor to be sure and have an accurate RPM reading. The tach is a prototype of a new line we are about to release, if anyone is interested in more details please drop me a PM.
You may be, my 6.9 that I had was an 83, so it didn't have the option of a tach, so I can't be of help from that end.So am i stuck having to use the PSD instrument cluster?
I was thinking that too but it think the tachs have a different sweepYou may be, my 6.9 that I had was an 83, so it didn't have the option of a tach, so I can't be of help from that end.
Just thinking out loud here, but maybe you can take the guts of the PSD tach, and put them into the back of the older instrument panel.