[cdansie]

I have a C4 behind a 5.0L EFI engine in a '29 Ford Hot Rod. I am running a Pricol electronic speedo and a Ford electronic speedo sensor. I have a couple of questions
1 Is there a way I can measure the pulses per revolution of the tailshaft?

2 The speedo sensor has 3 wires - 1 white 1 black and 1 blue - I presume they are for power, earth and signal out of the box - but which is which

If I know the number of pulses per revolution I can calibrate my speedo using the dip switches and a pulse chart

 

[WBT56]

Speedo sensor is hall effect. Does your speedo have a "hall effect" or "square wave" input? This is the terminal to use. Black wire is reference earth. I believe white is power in and blue is signal out. Don't worry about the pulses, just calculate engine rpm at 100km/h in top, based on tyre size and diff ratio. Jack up the back end securely, spin it up and flip switches until you get it close. You may need to fine tune after driving, to allow for converter losses.

 

[cdansie]

Thanks - I will try that