Hello,

The only VW part of this is that I was in my bus when I observed an old IH 
Scout with an odd light behavior.  Its headlights, tail lights, and even 
turn signal lights when on, wobbled in intensity with respect to the speed 
of the vehicle.  It looked about a 20% change in brightness that occurred 
about once per wheel rotation (a clue?) with about 1/2 the time at either 
of these distinct levels.

The puzzle to me is what could cause this?

My first thought was a lack of a good ground between the alternator and the 
car frame.  However, even if all the various ground straps were missing, I 
can't imagine that the ultimate connection through various universal joints 
and bearings would yield such a regular and clearly two level conductivity.

Friday is for sharing ... thanks for listening.

Mike