1982 Honda CB 650 -- Electrical / Charging problems (as usual) - Page 2

 ok guys, so i was reading the fault finding chart... and where it says
on the first page "Count the # of DIFFERENT wire COLORS coming from the
RR... I have 5. It looks like this:
http://i16.ebayimg.com/01/i/06/f5/df/8d_1.JPG  so in that case, which
one is this? is it the regulator, or the rectifier? and if so, where is
the other one so I can continue down my path of checking...

 
ben@spidre.com wrote:

"RR" stands for "regulator/rectifier". (one piece)

This looked pretty reasonable at a quick glance.
Looks like your three yellow might go to the stator ?

http://www.sportbikez.net/phorum/read.php?13,118915

see how it compares to your fault finding chart.

 
ben@spidre.com wrote:

Well, how many wires come from the alternator? If there are five wires,
the three that are the same color would be the three AC output phase
wires, and the other two would be the field excitation wires for the
stator, if it's an excited field alternator.

I went through all this with somebody else last year and I just deleted
the files from the workshop manual he sent me. Maybe it was you, and
you didn't just buy the motorcycle?

The typical stator has three phases, A, B, and C and they are connected
together in the center point, which is called "neutral". This is called
"Wye" or "Y" wound. If you imagine a Merceded Benz emblem with curly
arms, that would be the symbol for a three-phase "Y" wound stator.

You should be able to put your ohm meter on the R x 1 scale and read
from A to B to C and the readings should be the same, something like 1
to 3 ohms. If one phase reads lower than the other phases, the enamel
insulation has broken down and that phase is short circuit to itself.

Neutral isn't supposed to be grounded, so switch to the R x 1000 scale
and read from A, B, and C to the engine case. You should get a very
high reading, maybe 500,000 ohms or more, as the alternator stator is
not supposed to be grounded.

That would indicate that the stator is OK.

Then, if you have the five wire excited field alternator with brushes,
you can read from the black wire to the white wire through the brushes
and slip rings to check out the
windings on the stator itself. As I recall, it should be a few ohms
through the stator winding on the R x 1 scale, and the stator shouldn't
be grounded when you read the R x 1000 scale.

If your alternator is an excited field type with brushes, you should be
able to put your voltmeter probe on on either one of the brush
terminals and turn on the ignition key and get 12 volts DC with the
engine not running.

As to the regulator's AC to DC rectifying function, there are six power
diodes inside the heat sink, and you can check three of the diodes by
selecting R x 1 on your ohmmeter and going from each of the yellow
leads to the DC output lead from the rectifier. If you don't get the
same reading on all three diodes, one of them is blown out.

Then reverse your leads and check from each of the yellow leads to the
negative output wire on the regulator. Same thing, if any diode is
blown out, that diode will read too high.

If you're really confident about your understanding of brush type
alternators you can try external excitation while the engine is running
to see if the alternator puts out
enough voltage.

I was telling the other guy that if he wasn't sure about his voltage
regulator function, he could apply 12 volts from the battery to the
black or white wire and use the other wire as a return to the battery
to simulate the transistor in the regulator being functional. The
transistor is supposed to conduct current normally and then when
voltage gets too high, it shuts off the 14.5 to 15.5 volts coming from
the battery.

The test I described would be done with the engine running, and maybe
you'd want to
put a small amperage fuse in the circuit while you were trying to
excite it manually.

 
ben@spidre.com wrote:

That picture appears to show a rectifier/regulator unit with two
connectors. The one with the three yellow wires appears to also have
the DC positive and negative leads going to it. And the large connector
appears to be hiding a smaller two pin connector that has the voltage
regulating output and return (black and grey) wires.