The Rabbit TDI Project
Part 5: Wiring 2: the cluster and speedometer
Or: CXVII kph (117 kph)
My TDI engine has an Immobilizer.
For this engine to run, the engine ECU has to talk to the cluster to get the OK to run.
You start the car, the engine computer talks to the cluster to get the OK to run,
the cluster scans the key, and if everything is OK, tells the engine to keep running.
Ok, so I have to use one of those fancy backlit clusters. Cool.
No, wait, I have to fit that behemoth into a Rabbit dash. (shudder)
But that's all another story.
My engine didn't come with a cluster, I had to find one. I ended up talking to Komet on TDIclub and buying a new European cluster with MFA.
If it's worth doing, it's worth doing right.
So anyways, wiring the cluster was pretty simple, though I still don't have the fuel gauge working, but that's a little thing.
Ok, wait. How will I get the speedo to work? The A4 gearboxes are totally different, and drive an electronic speed sensor off of the final drive. My 020 gearbox had a mechanical cable driven off the secondary shaft. Not only that, the tires on my truck are totally different in size than the footwear of the A4 cars.
Solution: Mixing generations, and a wonderful black box.
The A3 cars use an 020 transmission and run an electronic speedo.
But then there is the issue of tire size and the reading location of the sensor.
The solution came from http://www.dakotadigital.com/Detail....Dakota Digital and a neat little SGI-5 speedometer and tach interface. This little unit is designed to manipulate a speedometer signal to scale up or scale down.
On the first drive of the truck, using a buddy's GPS, I found out that my speedometer was reading about 42% slow.
69 kph on my speedometer was ~117 kph in the eyes of the law. Flip a few dip switches on the SGI-5, and 117kph is 117kph.
Dakota Digital also makes the SGI-6 for Harley Davidson Motorcycles.
"Allows simple push button correction
of speedometer reading (from 200% to
50% of current reading) after a
transmission, gearing or tire size change"
Or, install this unit and when your speedo says 25MPH, you're actually travelling 50MPH, so you can cut in half the number of miles you put on your Harley.
summary: magic black box for the speedo
Part 1: Introduction
Part 2: Installing the Engine
Part 3: Transmission
Part 4: Wiring 1
Part 5: Speedometer and Cluster
Part 6: ImmobilizerIII
Part 7: Drive By Wire
Part 8: Intercooler
Part 9: Intake and Exhaust
part 10: MFA and Cruise Control
Part 11: The Dash
Part 12: The Little Things
Part 13: The End (for now)
Part 14: 6spd transmission and brake upgrades
One Year Later
Who Needs a VR6