> I don't know the WBX that well so was curious. Is this the Hall Sensor?

Yup - the little box below the coil.

> Bentley shows method for checking. Doesn't seem too hard. Maybe use a
> standard VOM??

I played with that, and it seems to be the problem.

> One is:  "Fairchild, Bosch and Siemens ... Build #33"
> Other:    "Fairchild and Telefunken (AEG).... Build #35"
> Any of that corresond to markings on yours?

Unfortunately the only markings are the pin numbers :o(

toodle pip,
--
       Dug Smith         | Terry Pratchett: It's almost
(mailto:dug@dugbert.com) |  impossible to ride a rock and roll
(http://www.dugbert.com) |  motorbike and stay on for three verses.