I had the most wonderful walkthrough by a very patient TwoTired. I figured I would repost the finer points with a little editing to streamline.
Stock bike draws about 10 Amps/120 watts
Even the Cb550 will make 150W when revved; CB750, 210W
Quote from: Mercuno on September 18, 2011, 09:02:30 pm
"After a battery reaches a certain voltage it just absorbs it somehow---give it 100 volts and it will stay at 14v no matter. I just dunno about the amperage line of thinking. "
You are wrong about that, I'm afraid. If you simply apply 100 Volts, the battery will reach full charge of 14.5 -15V and then continue to absorb power and dismantle the electrolyte via electrolysis. The power literally separates the oxygen and hydrogen from the electrolyte and liberates it into the atmosphere. It looks just like it is boiling. When the electrolyte level diminishes, the battery increases in heat. Continued power input can warp the plates, melt the plate separators, and permanently destroy the battery. The voltage regulators in the system are there to prevent this occurrence, and effectively shut off or diminish the alternator output when the battery is fully charged.
Tells us or show us what meter you are using for the tests. Like motorcycles, all the different models have slightly different behavior. If you operate it or set it wrong, the readouts will be mystifyting.
You will need to learn how to measure resistance of the white and green wires when disconnected from the regulator.
Same for the yellows of the Stator, to each other and to engine case.
Can we assume the wiring is stock?
The rectifier wouldn't care about being bathed in oil. Spend money on a R/R if you want to. But, I haven't found that at all necessary. I have both rectifiers and Vregulators that are 30+ years old and still working as they should.
It's your money, though.
There is absolutely no need to remove the rotor. It is just a lump of steel.
To find resistance, you set it to the lowest ohms scale. 200 is the one.
Note the display when the probes are separated and then touching each other.
Then apply the probes to the white and green wires disconnected from the Vreg.
Report the 3 readings.
Do the same thing to the yellows between each, and each to engine case. Report the readings.
We can check the rectifier next using a different meter setting.
do not measure the black wire, which, if the key was on will be +12V from the battery terminals. You should NEVER apply an ohm meter to a powered circuit. At best the reading will be nonsense, at worst, the meter will be damaged by the external power source.
dont touch the probes with your fingers when you test resistance,itll be going through your skin aswell and upset the reading,your meter should have a fuse inside that will blow if you do something like apply voltage when its on restistance setting,in which case the meter will go dead,if its battery is old itll be a good idea to replace it with a better one than what came in the meter.
I set the meter on 200 ohms- the readout says 1 without probes touching. Readout says 1.8 when touching probes.
When probing the white and green wires(that go directly into the regulator)(but having them disconnected from the regulator) the readout says 7.2
In between the yellows I get 4.2 across the board.
yellows to frame/ground/case readout says 1...
I have noticed that everytime I turn off the meter when I turn it back on and then touch the probes together I get a different reading. I know I am ignorant as to how this operates but I am trying to figure it out. I apologize but Please grade me on a heavy curve.
I just went outside and turned it on and all at once I checked everything when not touching each other the readout says 1 when touching the readout says 4.0
white to green wires read 11.7...
I did inbetween the yellow wires and get 4.2 in any order
Yellow to ground/case/frame readout says 1.
If I didn't have the same meter to mimic the tests, your response leaves doubt (not a good thing when dealing with electricity).
You have a 4 digit display. A number 1 without a decimal indicates infinity ohms (probes unconnected). Infinity is an important concept in understanding electrical operation, as infinitesimal current and power flow through such resistances. Your meter displays 1.8 when it actually detects a direct short. This is also an important distinction. And, it also means you will have to subtract 1.8Ω from any measurement you make with that meter and test lead set up. And, if you test an electrical path or device where 1.8Ω is displayed, then that path or device tested will conduct all the power and current that is available to flow. (This can be good or bad, location dependent.)
Quote from: Mercuno on September 20, 2011, 01:31:06 pm
When probing the white and green wires(that go directly into the regulator)(but having them disconnected from the regulator) the readout says 7.2
Subtract the 1.8 from 7.2 = 5.4Ω The nominal field coil resistance is 4.9Ω + or - 10%.
So, you have a good field coil and needn't worry about replacing that or having it damage a replacement regulator.
See? This is actual progress! You now know something in your system is good and you can shift your focus to other portions of the circuit!
Quote from: Mercuno on September 20, 2011, 01:31:06 pm
In between the yellows I get 4.2 across the board.
yellows to frame/ground/case readout says 1...
This is a difficult measurement to make with accuracy. You must again subtract your test tool error of 1.8Ω. 4.2Ω minus 1.8Ω equals 2.4 Ω. While Honda states that 0.35Ω + or - 10% is what it should be, the accuracy of your meter is within 1-10 digits. These digits can be added or subtracted from any reading shown on the display, depending on what mode the selector knob was placed. Since all your readings were the same, and it is rather rare for the stator to go bad without some physical trauma, I'd declare it both good and safe to use in circuit.
The 1 (or infinity) indicates the yellow wires aren't shorted to the the casework. This is good and another known added to our database of facts.
Quote from: Mercuno on September 20, 2011, 01:31:06 pm
I have noticed that everytime I turn off the meter when I turn it back on and then touch the probes together I get a different reading. I know I am ignorant as to how this operates but I am trying to figure it out. I apologize but Please grade me on a heavy curve.
It is important to declare what the meter's selector knob position is in when making such a report.
Assuming you are still in the 200Ω scale...
The meter supplies power for the circuit it is testing. Touching the probes together completes a circuit, and the tool attempt to measure the power or current that is conveyed when the probes touch each other. Display variations can come from tool inaccuracy/tolerances, or actual changes in the surface contact resistance between the probe tips. The probe tips can be contaminated which can add some small resistance to the test circuit. Unless the probe tips are gold or platinum, a slight oxidation film can form on the metal surface. The resistance is very small, particularly when very small current flow through the contact, which the meter provides. If you want to eliminate or reduce this, rub the probes together to wipe it clean, or use the tips/points to pierce the oxidation.
Quote from: Mercuno on September 20, 2011, 01:31:06 pm
I just went outside and turned it on and all at once I checked everything when not touching each other the readout says 1 when touching the readout says 4.0
white to green wires read 11.7...
It is clear that your instrument is not in the lab reference type category.
Still, it told you and us things needed to be known, both about the circuit being tested and the test equipment itself.
Sometimes, even if a wrench and bent and twisted, it can still serve. A torque wrench that is known to be off by 5 lbs, can still be used with purpose, using that knowledge.
Anyway, it looks like the alternator itself is a good unit. Three components left: Rectifier, Regulator, and interconnect wiring.
See how much more you know now?
Want to test the remaining components you have using other test tool functions? Or, is your heart still set on replacement?
Cheers,
I assume you'd like to test the Rectifier next?
Disconnect it from the wire harness. Test it "out of Circuit".
The meter selector will be changed to the position next to 200Ω, on the symbol that looks like -<|-.
This is the diode setting, which makes the meter supply enough voltage to turn on functional diodes and make them conduct.
There are six diodes in the rectifier. Their purpose is to convert the AC current made in the alternator, to DC current which can be used by the battery to restore power that was drained from it. The diodes do this by only allowing current to flow in one direction. You will now test them for this correct function.
Select a probe polarity and apply the probes to each yellow wire and the green wire. Record the 3 meter readings.
Now switch the probes, which reverses the polarity, and again apply them to each yellow and green wire. Record the 3 meter readings.
That just tested three of the diodes.
Now do the other three by applying the probes to the yellow and RED terminals. Record the 3 meter readings.
Again switch the probe polarity test the yellow and RED terminals again. Record the 3 meter readings.
What you should have as a result is six readings that are very high, and six readings that are very low. This would show that each diode will conduct current in only one direction. If any diodes are burned open, they will never show a low reading. If any diodes are shorted, they will never show a very high reading. You should now know if your rectifier is good or bad.
If you want to move toward testing the wiring components. Then disconnect the battery at it's terminals. Then set the meter back to the 200Ω scale. At the bike harness connector where the rectifier plugs in, place one probe on the green terminal and the other probe on the battery NEG cable terminal (NOT the battery itself). Record and report the reading.
Repeat the same test probing the Red connector terminal and the battery POS cable terminal. Record and report the results.
What you are looking for in both these tests is very low resistance in both cases, which shows proper connectivity of the charging system components to the battery terminals.
Next we will do voltage testing.
Move the selector knob on the meter to the DCV 20 position.
Place the probes on the battery terminals. A fully charged battery that has been removed from the charger for two hours should read between 12.6 and 12.8V. Tell us what your battery tests.
If you have found no faults or tests that are out of limits so far, then reconnect the battery and the rectifier to the bike. Find a separate insulated wire that you can attach between the battery POS terminal and the White wire to the alternator. (Assuming the Vreg is removed from or unconnected to the bike harness.) Alligator clips would be of help here.
Start the bike and monitor the battery voltage. Record and report the voltage at 1000 RPM and in 1000 RPM increments up to 5000 RPM.
Discontinue the testing if or when the battery voltage rises to 14.5- 15V. Such an indication will prove the alternator capable of charging the battery.
Which leaves two more tests.
With the bike not running and the key switch on, the black wire to the Vreg should have battery voltage on it. Probe any green connection, (or battery NEG terminal) along with the black wire, and you should see 12.(something) volts, or whatever the battery voltage potential is.
If that is what you get, then the last thing to test is the Voltage regulator.
Let me know when you get this far, and we can continue from there. If the bike still won't charge the battery with the Vreg you have installed, we can find out why or perhaps even fix it with a light massage.
Ok TT thank you for your patience . I tested the rectifier and voila'.
Diode setting:
probe from green to each yellow reads:
1=1 or infinity
2=infinity
3=infinity
when reversing polarity it reads:
1=528
2=518
3=537
from red to yellows:
1=infinity
2=510
3=infinity
reversing polarity it reads:
1=infinity
2=infinity
3=infinity
I then disconnect battery.Set meter @200 ohms. touching probes gets 3.3
from green to neg wire reads=3.3
from red to pos wire= 3.2
I never thought I would be so happy to find out I had a bad rectifier..lol
