Author Topic: not charging...straightening out my electrical (Read 8798 times)

laser145 · « **Reply #50 on:** July 29, 2010, 06:13:32 PM »

okay, I'll try again...

TwoTired... I actually did the test with the key on also. I figured the entire system would be dead with the key off.

thanks for the help guys, I couldn't do this without all the handholding!

Cheers

VTSteve · « **Reply #51 on:** July 30, 2010, 10:11:35 AM »

Sounds like you have a faulty rotor. It's very easy to test. Pull the alternator cover off, 4 bolts. Set your multimeter to resistance. There will be 2 rings on the rotor. Test the resistance between the rings. It should be around 5 ohms. Much less than that means it has an internal short, and will cause the exact symptoms you're describing.

TwoTired · « **Reply #52 on:** July 30, 2010, 10:16:22 AM »

Quote from: VTSteve on July 30, 2010, 10:11:35 AM

Sounds like you have a faulty rotor. It's very easy to test. Pull the alternator cover off, 4 bolts. Set your multimeter to resistance. There will be 2 rings on the rotor. Test the resistance between the rings. It should be around 5 ohms. Much less than that means it has an internal short, and will cause the exact symptoms you're describing.

Admire your desire to help. But the CB750 SOHC4 doesn't have a slip ring rotor and the field coil is stationary and 7.2Ω per manual.

Cheers,

VTSteve · « **Reply #53 on:** July 30, 2010, 11:45:50 AM »

Whoops, thought it was a 650.

Thanks!

laser145 · « **Reply #54 on:** July 30, 2010, 04:09:01 PM »

So I disconnected the white and black wires from the regulator and wired them together... started the bike.

Touched the probes of my multimeter to the battery + and - ...(my battery has been on it's trickle charge for the last 24 hours)

The reading was 12.5, and it never changed as I revved the bike up to 5000 RPMS

next!

TwoTired · « **Reply #55 on:** July 30, 2010, 04:12:50 PM »

Did you measure the voltage going to the Field coil during that test?

laser145 · « **Reply #56 on:** July 30, 2010, 04:15:16 PM »

Quote from: TwoTired on July 30, 2010, 04:12:50 PM

Did you measure the voltage going to the Field coil during that test?

How do I do that... all I've done are the tests that Spanner1 has given me above. I've got the Honda manual, but it's pretty vague.

TwoTired · « **Reply #57 on:** July 30, 2010, 04:29:03 PM »

If you bypass the regulator by connecting it's white and black wires together, you measure voltage at that connection point with the red probe and place the black probe on the green wire connection at the Vreg.

We must know that the field coil is being powered, as the alternator cannot put out any power without the field coil activated.

Another thing you can do is take a very thin feeler gauge (steel, not stainless), or a magnet, and hold it near to the alternator case while you turn on the key switch. The magnetic field created by the electromagnet should draw in the feeler gauge tip (or magnet), indicating the presence of a magnetic field.

Once you know there is a magnetic field in the alternator, we can then probe the output for reasonable voltage.

Cheers,

laser145 · « **Reply #58 on:** July 30, 2010, 05:07:50 PM »

Quote from: TwoTired on July 30, 2010, 04:29:03 PM

If you bypass the regulator by connecting it's white and black wires together, you measure voltage at that connection point with the red probe and place the black probe on the green wire connection at the Vreg.

We must know that the field coil is being powered, as the alternator cannot put out any power without the field coil activated.

Another thing you can do is take a very thin feeler gauge (steel, not stainless), or a magnet, and hold it near to the alternator case while you turn on the key switch. The magnetic field created by the electromagnet should draw in the feeler gauge tip (or magnet), indicating the presence of a magnetic field.

Once you know there is a magnetic field in the alternator, we can then probe the output for reasonable voltage.

Cheers,

I bypassed the regulator by connecting the black and white wires together, then I placed + probe on the junction and - probe on the green wire at the regulator... my reading was about 11.5... hard to tell exactly, but the voltage was definitely lower than at the battery.

Also, I don't have steel feeler gauge with me, but my screwdriver head is magnetic... when I turn on the key it seems like there is a very slight magnetic field created... it's almost unnoticeable, but I'm pretty sure I felt it.

...

Spanner 1 · « **Reply #59 on:** July 30, 2010, 05:08:53 PM »

Already done TT... OP, now do the feild coil test ( meter set at 10x) described above, ign. off , white and green disconnected from regulator and probes applied ( doesn't matter which probe to what wire ) just green and white... reading needs to be 7.2 ohms or very near that reading (within +1 ohm).............. Well?

laser145 · « **Reply #60 on:** July 30, 2010, 05:28:01 PM »

Quote from: Spanner 1 on July 30, 2010, 05:08:53 PM

Already done TT... OP, now do the feild coil test ( meter set at 10x) described above, ign. off , white and green disconnected from regulator and probes applied ( doesn't matter which probe to what wire ) just green and white... reading needs to be 7.2 ohms or very near that reading (within +1 ohm).............. Well?

Meter set at 10x, white and green disconnected from the regulator and probes attached... no volts... no volts with the engine off no matter what the key position, no volts with the engine on...

TwoTired · « **Reply #61 on:** July 30, 2010, 05:34:17 PM »

Quote from: laser145 on July 30, 2010, 05:07:50 PM

I bypassed the regulator by connecting the black and white wires together, then I placed + probe on the junction and - probe on the green wire at the regulator... my reading was about 11.5... hard to tell exactly, but the voltage was definitely lower than at the battery.

Did you have the headlight on? Losing a volt between battery and regulator would you say?
You could try running a wire direct from the battery POS terminal to the White wire. Run the engine and check for voltage rise at the battery terminals.

Do test for field coil resistance, disconnected from verg. Use an ohms scale.

When you are confident about the Field coil resistance and power to it. Then check for AC volts on the yellow wires. Black probe on Rectifier green, and red probe on each of the yellows out of the harness from the alternator. If your yellows connect to white on the rectifier, either note that mentally that they are logically yellow or paint them sum#$%*es. There should be about 60Volts on the AC lines, assuming they aren't loaded down too much by the system.

Cheers,

laser145 · « **Reply #62 on:** July 30, 2010, 05:39:28 PM »

Quote from: TwoTired on July 30, 2010, 05:34:17 PM

Quote from: laser145 on July 30, 2010, 05:07:50 PM
I bypassed the regulator by connecting the black and white wires together, then I placed + probe on the junction and - probe on the green wire at the regulator... my reading was about 11.5... hard to tell exactly, but the voltage was definitely lower than at the battery.
Did you have the headlight on? Losing a volt between battery and regulator would you say?
You could try running a wire direct from the battery POS terminal to the White wire. Run the engine and check for voltage rise at the battery terminals.

Do test for field coil resistance, disconnected from verg. Use an ohms scale.

When you are confident about the Field coil resistance and power to it. Then check for AC volts on the yellow wires. Black probe on Rectifier green, and red probe on each of the yellows out of the harness from the alternator. If your yellows connect to white on the rectifier, either note that mentally that they are logically yellow or paint them sum#$%*es. There should be about 60Volts on the AC lines, assuming they aren't loaded down too much by the system.

Cheers,

The headlight was on... can't shut it off on the K6(annoying). I'll have to get back on these tests tomorrow, the misses needs my attention for the evening as I've been at work all week.

Cheers guys, thanks for your considerable time...

TwoTired · « **Reply #63 on:** July 30, 2010, 05:47:53 PM »

K6 has a headlight fuse that, if removed, will douse the headlight. This will relieve the load on the battery (about 5 amps) while troubleshooting.

Cheers,

Spanner 1 · « **Reply #64 on:** July 30, 2010, 06:54:59 PM »

Laser... wait-up, we are NOT looking for voltage in the last ( field coil ) test.... ignition is OFF and wires are disconnected from the regulator. We are looking for the impedance of the feild coil which is why the meter is set on OHMS not VOLTS, the 10x ohms setting.... please tell me what the reading is ( waiting patiently for 2 days, trying to help)

You say 'no volts' when you should be saying ' no continuity' . Continuity = when you touch the probes ( on OHMS setting ) together and the needle swings all the way = continuity = 0 ohms..... so if the needle did not move in the last test your Feild Coil is kaput and 'open circuit'..... bad feild coil which is one of the 3 components of the alternator under the left-hand cover....... (phew!)

laser145 · « **Reply #65 on:** July 30, 2010, 10:07:42 PM »

TwoTired... Do I need to remove this fuse to increase the accuracy of my determinations through these tests?

Spanner1...I did the test wrong, tomorrow morning I'll get it right and report back.

If you guys lived in NYC I would be done with this and you would be the proud owner of a bottle of whiskey!

I'll check back in the morning.

TwoTired · « **Reply #66 on:** July 30, 2010, 10:46:41 PM »

Quote from: laser145 on July 30, 2010, 10:07:42 PM

TwoTired... Do I need to remove this fuse to increase the accuracy of my determinations through these tests?

No. It just helps keep the battery healthier longer.

laser145 · « **Reply #67 on:** July 31, 2010, 11:48:46 AM »

Quote from: Spanner 1 on July 30, 2010, 06:54:59 PM

Laser... wait-up, we are NOT looking for voltage in the last ( field coil ) test.... ignition is OFF and wires are disconnected from the regulator. We are looking for the impedance of the feild coil which is why the meter is set on OHMS not VOLTS, the 10x ohms setting.... please tell me what the reading is ( waiting patiently for 2 days, trying to help)
You say 'no volts' when you should be saying ' no continuity' . Continuity = when you touch the probes ( on OHMS setting ) together and the needle swings all the way = continuity = 0 ohms..... so if the needle did not move in the last test your Feild Coil is kaput and 'open circuit'..... bad feild coil which is one of the 3 components of the alternator under the left-hand cover....... (phew!)

I redid this test set 10 ohm setting... The needle went all the way up

Spanner 1 · « **Reply #68 on:** July 31, 2010, 12:44:13 PM »

X10 ohms and the needle went all the way over !, well looks like a shorted-out Field coil, or your little analogue meter is not accurate enough to read as low as 7 ohms.... if I had an analogue meter I'd try if on my Field coil to see what it reads, maybe someone reading this could do that.... with my digital meter my Field coil ( tested on the white and green wires ) reads right at 8 ohms ( Spec is 7.2 ohms ).

TwoTired · « **Reply #69 on:** July 31, 2010, 02:59:34 PM »

What does the 10X scale deflect to when you simply place the probe tips together?

laser145 · « **Reply #70 on:** July 31, 2010, 04:09:08 PM »

Quote from: TwoTired on July 31, 2010, 02:59:34 PM

What does the 10X scale deflect to when you simply place the probe tips together?

Needle goes all the way up...

laser145 · « **Reply #71 on:** July 31, 2010, 04:18:27 PM »

Quote from: Spanner 1 on July 31, 2010, 12:44:13 PM

X10 ohms and the needle went all the way over !, well looks like a shorted-out Field coil, or your little analogue meter is not accurate enough to read as low as 7 ohms.... if I had an analogue meter I'd try if on my Field coil to see what it reads, maybe someone reading this could do that.... with my digital meter my Field coil ( tested on the white and green wires ) reads right at 8 ohms ( Spec is 7.2 ohms ).

I wanted more accurate readings so I bought this

It doesn't have a setting for 10x OHMS, so I ran the test on all the OHM settings...

@20K... .01 Ohms
@2000... 8 Ohms
@200... 8.1 Ohms

TwoTired · « **Reply #72 on:** July 31, 2010, 05:42:17 PM »

On the 200 Ω scale, what is he reading with just the probe tips together. Whatever it is, you must subtract that from the measurement.

laser145 · « **Reply #73 on:** July 31, 2010, 05:59:46 PM »

Quote from: TwoTired on July 31, 2010, 05:42:17 PM

On the 200 Ω scale, what is he reading with just the probe tips together. Whatever it is, you must subtract that from the measurement.

The numbers go crazy for a bit, then settle on .4

TwoTired · « **Reply #74 on:** July 31, 2010, 06:05:41 PM »

So subtracting 0.4 from 8.1 yields 7.7 ohms. You might examine/clean the connections in the path to the alternator field, but it should work.

Ready to check AC output?

I hope you aren't using the probes connected to the meter as in your picture.

Cheers,

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Author Topic: not charging...straightening out my electrical (Read 8798 times)

VTSteve

VTSteve