>  Someone, I think
> John Bange, started to map the circuitry but it seems to be a project that
> died. I have taken the defective unit apart and seems almost comical in its
> design and construction - so many resistors, transistors and capacitor!
> None
> of them appear damaged to my eye so I'm wondering what has failed.
>

Yeah, I got about 10% done with that before I realized that That Way Lies
Madness. It is almost comical in its design. It's a fantastic bit of
hand-tuned analog circuitry, a throwback to a simpler age. It's almost
steampunk in its fabulous complexity. I'm not sure why VDO went analog with
it. Perhaps digital microcontrollers were still just s little bit too
expensive.

I'm still working on a digital replacement. The controller and interface are
pretty simple--- just a few transistors and resistors with an Atmel chip.
I've already built a couple test units, and they actually worked. The hard
part for me is making something that doesn't fall apart. Automotive
applications just aren't very tolerant of my sloppy soldering style.

--
John Bange