Author Topic: Help verify Rectifier test results?  (Read 1935 times)

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Offline jph550

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Help verify Rectifier test results?
« on: August 10, 2006, 04:07:30 PM »
I have gotten around to testing my rectifier.
i think it is shot, based on the testing guidelines in the faqs. Any confirmation or advice would be great.
Results:
red lead to green and black to 3 yellows (in diode test mode); 541, 543, 531
black lead to green and red to 3 yellows (in diode test mode); 1, 1, 1

black lead to red/white and red to 3 yellows (in diode test mode); 529, 531, 543
red lead to red/white and black to 3 yellows (in diode test mode); 1, 1, 1

I tested the rectifier after taking it off of the bike.
I don't know what these numbers mean except they are different than expected results.
I'm still trying to understand what the rectifier does and what these numbers mean.

After testing this I also tested the voltage at the battery with engine running at 4000rpm and got a reading of 13.9 to 14.0 volts.
Is this good? The full load test (with igintion on headlight high and not running) was higher than 10.5V. Actuallly close to 12

The bike is running well enough, but I haven't been on any long rides and am hesitant to do so until I resolve these electrical questions.
Just when the heat is starting to brealk for the weekend here on the east coast.

peace,
jason
'76 cb550K
with original faded brown/green tank

Offline Bodi

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Re: Help verify Rectifier test results?
« Reply #1 on: August 10, 2006, 05:33:06 PM »
Well, not knowing your meter and what it should display on diode test, it's hard to say. The pattern actually looks fine, the 500 numbers are probably voltage drop: 531 could be 0.531 VDC which is a fine forward drop on a silicon diode. The "1" is a mystery though.
I would check the instructions for your meter. What does the meter read with nothing connected to the leads in diode test? Generally a good diode will read something like 0.5 V forward, reverse the meter reads like there's nothing connected.

Offline jph550

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Re: Help verify Rectifier test results?
« Reply #2 on: August 10, 2006, 09:27:55 PM »
Bodi,
Thanks for the feedback. I'll check the manual for the multi meter tomorrow and see what the numbers represent.

peace
'76 cb550K
with original faded brown/green tank

Offline bryanj

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Re: Help verify Rectifier test results?
« Reply #3 on: August 11, 2006, 01:30:34 AM »
Your bike is charging OK so why are you worried about the rectifier?
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline jph550

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Re: Help verify Rectifier test results?
« Reply #4 on: August 11, 2006, 07:07:14 PM »
Bodi and Bryanj,
Thanks again for the feedback. Not knowing what a recitfier is really supposed to do I panicked when I grounded out my solenoid cables and read some threads about fried electronics and over reacted.

Bodi,
The multimeter I have measures in mV when testing in diode mode. And 1 means nothing is going through. (still a little unclear on this though). I sound like your interpretation of my numbers is spot on.

Bryanj,
I agree and so does another mechanic I chatted up a bit. So, I'm going on a ride in the mountains North of NYC tomorrow and the hell with it.

Now its time to break in those new tires I put on the bike.  ;D

peace and thanks again.
jason
'76 cb550K
with original faded brown/green tank

Offline Green550F

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Re: Help verify Rectifier test results?
« Reply #5 on: August 11, 2006, 08:00:02 PM »
"1" is a typical indicator of over-range on digital meters. particularly if it apears on the left of the display.
as for the 5?? readings they are the forward voltage drop of the diode im millivolts. (this is the voltage it takes to drive electrons across the PN junction that seperates the positive and negative sides of the diode)

To explain why a diode conducts in one direction only... To simplify the analogy think of the to halves of the diode being charged like magnets. When charged properly the two halves pull together and allow electricity to flow across the center. if the applied voltage is reversed it is like flipping one magnet over. The mismatched charges want to repell and leave a "gap" in the middle causing the current flow to be stopped. Keep in mind that diodes are actually a solid material and the "gap" is actually a region in the material that is lacking in available electrons for proper conduction. They don't really seperate, Unless you exceed their current and voltage ratings. Then they do seperate nicely!
93 Kawasaki Voyager XII
70 Honda CL350 Cafe

Offline jph550

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Re: Help verify Rectifier test results?
« Reply #6 on: August 12, 2006, 05:24:30 AM »
bodi,
I forgot to indicate that in diode mode the meter I used reads 1 while nothing is connected.
thanks again

jason
'76 cb550K
with original faded brown/green tank

Offline Pinhead

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Re: Help verify Rectifier test results?
« Reply #7 on: August 12, 2006, 03:10:12 PM »
According to those numbers, your rectifier is good. However, that's not testing the regulator side of the system. Your rectifier can be good but regulator be bad. They're built into one, so you have to replace the whole unit. Look here to build a cheap R/R:

http://www.sohc4.us/forums/index.php?topic=12465.msg119198#msg119198
Doug

Click --> Cheap Regulator/Rectifier for any of Honda's 3-phase charging systems (all SOHC4's).

GM HEI Ignition Conversion

Quote from: TwoTired
By the way, I'm going for the tinfoil pants...so they can't read my private thoughts.
:D

Offline Bodi

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Re: Help verify Rectifier test results?
« Reply #8 on: August 13, 2006, 07:10:30 AM »
As far as I know the 550 has separate regulator and rectifier.

Offline Pinhead

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Re: Help verify Rectifier test results?
« Reply #9 on: August 13, 2006, 08:37:22 AM »
As far as I know the 550 has separate regulator and rectifier.

Oops... I need to pay more attention before I post lol.
Doug

Click --> Cheap Regulator/Rectifier for any of Honda's 3-phase charging systems (all SOHC4's).

GM HEI Ignition Conversion

Quote from: TwoTired
By the way, I'm going for the tinfoil pants...so they can't read my private thoughts.
:D