Yes, I don't know what exactly it is, but there's some device which fits inline with my speedo cable that provides the speed signal for the scooby ECU. The speed signal screws into the back of the speedo pod, and the speedo cable screws into the back of that.
Fellowes have cables made for them by a local company, speedy cables do something similar. Its longer than standard by around 6 inches. The speed sensor is similar to a hall sensor as I understand it. Unsure how essential it is, mine was disconnected for a while with no obvious side effects.
Think a speed sensor is pretty critical for power steering output.....but guess it all depends what set-up you have....
Agreed, my long term aim is to bodge in an electric power steering rack to do away with all the weak points in the standard system and speed control is a must. I remember when I were a lad we were friends with a loaded Canadian lad. We used to borrow his mothers Ganada Ghia and tootle down to London for fun and frolicks, it had really twitchy steering - full on power at 100mph is fookin dangerous. The dad wouldn't let us have his XJS
Very critical if full benefit is to be gained Finger tip light steering on a bay right through the speed range could be interesting.
I suspect that these vans had a tendency to drift sideways when buffetted even when brand new so any wear in the linkeage would exacerbate it. One curious thing I first observed with the PAS was although my stock steering was pretty good with barely discernable play this little bit seemed to dissapear or be taken up (corrected?) once under way. Somewhat illogical I know!
I figured that.... I'd say that was more logical as the weight distribution and rolling resistance will change when driving