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On 24 Mar 2005 at 20:32, Dave Hall wrote: > > And if a shorted generator would put up less rotational resistance, > > than a functioning one, then that doesn't really explain the mystery. > I think with a short circuit there could be a much bigger current flowing and > therefore more power being generated (even if only wasted in heat), resulting in > it being harder to rotate. I wouldn't assume that is the reason, but I think it > is possible. While this is a reasonable way to look at it, if it's much of a short then the generator's output voltage will drop and then there won't be enough field to sustain any output. I think that what actually happens in use is that the generator bootstraps itself up to 12-14V while driving only its own field windings. It can do this, because the field coil load isn't too large, but if the full car's load was there from the start then the generator would never manage to get itself started. This is one of the functions of the cutout relay in the VR. -- Jim Adney jadney@vwtype3.org Madison, WI 53711-3054 USA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~