Folks:

I'd posted some time back that the cruise control in my '91 Carat didn't work,
and that my local VW dealer couldn't figure out the problem.  Following the
test procedures in the Bentley manual didn't lead to a resolution.  Even the
$500 control unit was replaced.

A fine and very persistent independent VW mechanic here in Wilmington NC, Dave
Metz, finally figured it out.  Late-model Vanagon CC units pick up the current
speed via an inductive sensor mounted on the back of the speedometer.  (Earlier
units used a sensor on the axle, sez Dave, but the magnets had a tendency to
fly off.)  If you put an ohm meter across the two leads on this sensor and spin
the speedometer shaft, using a drill or other handy rotary device, you should
see pulsating variations in resistance proportional to the speed.  The sensor
on mine was dead as a doornail - no continuity at all, regardless of speed.  He
swapped in an identical sensor from the loose instrument pod of some different
recent VW (Jetta/Golf/dunno) that was conveniently lying around, and presto,
I'm cruisin'.

This part is probably cheap even from VW - it's just a little coil with two
spade lugs - but it can apparently be mined from other, more common VW models.
 Once you get the instrument pod out, the thing comes out with two little
screws.

Turns out my old control unit worked just fine, so we put it back on.  I guess
I have a spare now, unless someone out there needs one.

Thanks to those of you that offered suggestions.

-jch

--
Jerry Hudgins (jerry@e-farm.com)