VSS stuff

[AL8001 at aol.com]

I haven't tried any of this, though it should work.

As far as I can tell American cars use a 1000 rev per mile speedo ratio.  I
know for sure many cable driven speedo GM cars use a speedo mounted VSS
generator.  This gen consists of a LED and a photo reciever ( diode or a
transistor ) mounted in a small plastic holder ( ~1/2 X 1/4" X 3/8") , 12
inches of wire, and a buffer ( Yellow plastic ~ 1" X 1/2" X 3" )  From what I
remember it has three connections: 12 VDC in , Ground and Signal Out.

The LED / Photo in bolted ( with one small screw ) to the rear of the speedo
and looks at the u shaped magnet holder( shiny metal ) that is driven by the
speedo cable.  So. . . .  for each rev of the cable, the LED reflects back
twice for every rev.

1000 Revs Per Mile = 2000 Pulses Per Mile

Need 4000 per mile?  just add two more shiny ears to the magnet holder.
Instant 4000 PPM ! :+)

Don't have a GM car? With a little work you could add the LED/ buffer to most
any car. Just cut a slot and drill a hole.

Don't have 1000 rev per mile?  Most likely the ECM dosn't care if you have 800
PPM to 1200 PPM.  

Harold