[T3] Odd Electrical Gremlin - Voltage Regulator?

Jim Adney jadney at vwtype3.org
Mon Jan 30 21:15:34 PST 2012

On 30 Jan 2012 at 19:32, Robert Bills  wrote:

> Thanks for the quick response.  I have replaced the "generic" voltage
> regulator with the Bosch 9 190 040 099 E, and all seems to be working
> properly again.  The generator appears to be charging, but all I have
> to test it with is a basic voltmeter I keep in my toolbag in the car. 

You can really do the most important testing with just a voltmeter.

> Examination of the old VR revealed that the points were pitted, but
> not welded together.  Apparently they were sticking[?]  It also
> appears that the primary coil got hot at some point, but nothing more
> than slight discoloration.  Hopefully I didn´t fry the generator. 

It doesn't take much to weld them together, and this tends to happen 
once the pitting gets bad. My guess is that the pits create small 
"peaks" that make for a point contact that can get hot and melt.

"Primary coil"? In the generator or the VR? In the generator, we're 
concerned about the armature windings. You should be able to look in 
there and see if they've gotten really hot.

> Also, since I've been told that the case is "hot" on these solid state
> VRs, I placed a piece of 1/16" rubber gasket material between the VR
> and the body panel for insulation because the new unit is slightly
> wider than the original, leaving very little clearance. 

Right, a little air gap should be fine, but an insulator will protect 
you in case someone drops their keys back there.

Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA

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