May 26, 2008 · as far as i know they do not make one for the Transit. theres no way to switch it from the manual speedo cable to a electronic unit unless you change it to a OBD2 car with a ECM and all the bells and whistles that go with that. why dont you get the GPS sending unit that mounts on your roof of the car instead? it will track your speed and send the info to your sat nav setup.
A simple to use Transmission Speedometer Gear Calculator. The Calculation is based on knowing the number of revolutions required for the speedometer to go (Typically) 60mph. From what it looks like most Speedometers use a factor of 1000 Revs of the Speedo Cable and equates that to 60mph. Your mileage may vary.
A speedometer measures your car’s speed. There are two types of speedometers, and both work differently from one another. Mechanical speedometers take advantage of springs and electromagnetic waves, while electrical speedometers make use of magnetic sensors.
Nov 14, 2017 · GM Powertrain recently brought to my attention that pin 14 (grey/blue wire) out of the transmission will provide a non-CANBUS raw signal (pulse generated) that should drive a conventional electronic speedometer. This is an inductive type signal so voltage output is dependent on speed.