Off hand, I know the 90+ cars used '730 ECM's and did not use VSS buffers.. Were the gauges compatible with VSS buffers?

I'm confused on the wiring. Anyone care to give me a hand? I have a 2 wire (yellow/puprple) magnetic VSS with plastic gears. I want to use a 90+ electronic speedo cluster. I'm using a '730 ECM, on a re-pinned 165 harness.

-- Joe

 

you can set the ECM to use the speed signal from the sensor or from the buffer.
as far as i know, the signal from the buffer will run the newer speedometer ok & show the correct speed if you have the right gears on the sensor.

on my car im using the magnetic speed sensor that was used in the trucks. its a hi-res sensor that outputs 40 pulses per drive shaft revolution. i use a DRAC to output a speed signal to my speedometer, ECM, & cruise.
at one time i did use the speed buffer in the ECM & used the output from the ECM to my speedometer & cruise. when i was using the hi-res sensor, i was able to correct the speed reading using the VSS pulse per mile setting under Constants/Scalars in TunerPro.
it worked fine until up to a little over 60 MPH, then the speedometer started to show progressively slower speeds the faster i went. the speed reading in the data stream showed the same slow down. so i went back to using the DRAC. i don't remember if the VSS pulse per mile setting does anything to the speed reading using the DRAC as the input or not.
i believe the buffer in the 730 ECM can't handle the output of the hi-res sensor at higher speeds.

 

For my car, which is an 88 that I switched over to a '730 by repinning the '165 harness, all I did was input the VSS wires to the ECM like the normally would be. I also switched to the 90 style gauges, so I just used the output on the ECM and fed that to the speedometer. If you want to hook up the cruise there's another out put on the ECM for that.

from the VSS - A) yellow wire goes to B10 on the ECM, B) purple wire goes to B9 on the ECM.

From the ECM - B11 brown wire goes to the speedometer
- C1 goes to the cruise control