[TR] TR4 Voltage Reg/Igniton Light

Randall tr3driver at ca.rr.com
Wed Jan 30 14:20:10 MST 2008

> I find that the cut-out relay is still maintaining a slight 
> magnetic field 
> Does this still suggest the adjustment mentioned or is 
> something else at work?

That is what I assumed was happening, Geo, so it's at least consistent with
the cutout relay being out of adjustment.

The cutout relay has two separate coils on it, one of which senses the
generator current and the other senses generator voltage.  With the
generator stopped and the cutout closed, both coils are energized but with
opposite polarities.  There should be a point as it is coming to a stop
where they exactly balance and the relay drops out; but with it totally
stopped, the two coils do not balance and so there is a net magnetic field
attracting the armature.  IOW if you walk up to a normal, not running system
and mash the cutout contacts closed, they will stay closed.

It's possible there is something else wrong, but I can't think of anything
obvious that would cause the symptoms you describe, except maybe the
armature/contacts binding somehow.  And I think you would have noticed that
already.  If the shunt coil were open, the cutout wouldn't close when you
start the engine; and if the series coil were open, the generator would not
charge the battery.

I'm assuming it does charge normally otherwise ...


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