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On 15 Jun 2006 at 12:44, Will McCreight wrote: > So I am in need of your counsel: Gen Light has started to go on, on > startup, then goes out after about 5 minutes. Voltage gauge reads 12 > volts until light goes out, then rises to 14 or so. Have by now > replaced both the generator and the VR, but no change in behavior. It's odd that replacing both the VR and the generator would not have cured this. Are your replacements a new Bosch VR and a Bosch rebuild? It's possible that you have a wiring problem (poor connection somewhere), so you should check for loose push-on spade connectors on the generator and VR. If the replacement generator was not rebuilt, then I would suspect worn out brushes. For this symptom I generally suspect some shorted turns in the field winding, but these are hard to test for. You can measure the resistance between D+ and DF on the generator and compare this with the value in the Bentley manual, but it's generally hard to tell the difference. I agree that the odds of getting a bad replacement generator with the same fault are pretty low. > Should I conclude that this is a voltage drop caused by a short > somewhere? I will be exploring that possibility next. I think I must > be getting an electron loss which partially drains the battery, then > once the generator refills it, the voltage jumps back up to 14 v. Probably not a short, but maybe a poor connection. This is really a case of the generator not being able to "bootstrap" itself into operation. Other times when I've seen this symptom, it could be overcome by revving the engine. This is NOT a sign that your generator needs to be repolarized. Don't allow yourself to be led down that road. Your generator refreshed its polarization each time the light finally went off and the voltage came up to 14V. > I did take the battery to NAPA and their meter checked it out as OK. That's right, these are not the symptoms of a battery problem. -- Jim Adney jadney@vwtype3.org Madison, WI 53711-3054 USA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~