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New Rectifier tests bad

S

slapsomeducttapeonit

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"hello all,
I've got a BF

"hello all,
I've got a BF8A with a bad charging circuit. I checked the continuity between all the points on the rectifer, per the manual, and got nothing. The coil has continuity, and voltage when the engine was running.

So I figured great, shelled out $110 and bought a new rectifer.

Got it today, and figured I should do the same voltage check. Once again, I got no continuity between any of the points, except about 1.5 megaohms between red and green.

I'm pretty sure my meter works, is said 8 ohms on an 8ohm speaker, but I can't think of any standards I have in the 100K range.

Anyone else ever have problems with bad stuff coming from a vendor? I would think stuff like this would be tested at manufacture, but who knows...

I figured before I embark on a journey through returns hell, I should run this by ya'll so see if I'm doing something wrong..."
 
"My Honda Shop Manual just lis

"My Honda Shop Manual just lists tests for continuity:

Test probes +/-
Green/Blue no
Blue/Green yes
Blue/Red no
Red/Blue yes

You are changing AC from Charging Coil to DC,
with the DIODE RECTIFIER.

Diodes allow current in one direction (+/-)
but no current in the other (-/+).

The Charging Coil test lists 0.13 OHM across the two leads,
but no OHM value listed for Diode Rectifier.

Confirm a good battery inside your Volt/Ohmmeter.
"
 
"That's what I've done

"That's what I've done, tested for continuity IAW the shop manual. My manual does give resistance values, and when it comes to testing continuity I usually just set the meter to measure ohms, and if I get ohms, I consider it to be continuous. I get nothing, even with the meter set to the highest range.

I just find it odd that I've gotten the same results with the one on my engine and the brand new one (i.e no continuity anywhere). Makes me suspicious that I'm not doing something right, but a continuity check is about as simple as it gets."
 
"Pilot - My manual says differ

"Pilot - My manual says different that what you suggest above, just for the first two though..

probes +/-
Green/Blue Yes
Blue/Green No
Blue/Red no
Red/Blue yes

Regardless, I don't get good continuity anywhere... My meter goes up to a maximum of 2 Megaohms. I also used a meter at a local radio shack, and for the values that exceed the capacity of my meter, their meter reads about 3-5 Megaohms. I also put a new battery in my meter, So know now it’s not my meter.

Red lead on Red, Black on Blue (spec 1k-200k) - No continuity on either blue wires (greater than 2 Mega ohms)

Red lead on Red, black on green (spec 500-100k) – 1.52 Mohms measured

Red lead on Green, black on blue (speck 100-50k) - No continuity on either wire (greater than 2 megaohms)

Did the diode check on my meter too, and only the diodes on the green side tested ok. Yet, even they showed very high resistance when tested for resistance. (well beyond the 100-50K spec, they tested over 2 mOhms)

So I'm thinking I got a bad rectifier shipped to me. I just bothers me when I see the same errors on the existing one that I do on a new one... makes me think something is wrong with what I'm doing."
 
"My Shop Manual is the Honda M

"My Shop Manual is the Honda Marine BF75-BF100-BF8A from Honda Dealer.

Diode Rectifier shows list of $66 and price of $52.80 from:

http://www.boats.net/parts/search/Honda/Outboard%20Engine/parts.html

I have had good result with online purchase from them and even better service
(when I had a question) by using their toll-free service:

<i>
Phone, Fax & Address
Speak with a customer service team member by telephone.

Primary: 877-408-1499
Secondary: 863-465-6669
Fax: 1-801-881-1039


The OutdoorNetwork Corporation - Boats.Net Store
730 US Hwy 27 North
Lake Placid, Florida 33852


Our hours are Monday through Friday, 8 AM - 5 PM Eastern.
Here is a Map & Directions to our store.
Click to expand...
</i>

Suppose it is unlikely for new units to be tested before shipment,
since it would be so rare to find a defect, hope you can rectify your problem.
"
 
"I'm not a big fan of usin

"I'm not a big fan of using multimeters for testing diodes. The best way to test diodes (especially power ones) is to build a tester with a battery and a lamp. Normally, diodes fail catastrophically, i.e., either short or less often "open". By short, I mean that they will pass current in both directions, by open...in neither direction. If you are inclined to "cobble up" a tester from a few parts, let me know and I will post the instructions on how to do this. Its just enough work for me to do it, that I won't unless there is an interest."
 
"I bought the rectifer from th

"I bought the rectifer from the outdoor network, and they've agreed to exchange it. They agreed continuity in excess of 3Mohms is not right. I'll let ya'll know when I get the new one.

Pilot, I've got the same manual, and did the same search, but it came back at $110 each by the time I selected 1998 and extra long shaft 8hp. It's beyond me why there would be such a difference."
 
"My Honda Manual has BF75-BF10

"My Honda Manual has BF75-BF100-BF8A printed on the cover.

It is 'loose-leaf' and BF8 is only covered in last seven page (101-107) <supplement> describing "major differences" and reference to base shop manual p/n 6188223 "for information not covered...".

...However.. Now I see that page 11-12 in front of same manual is for the "BF8A Regulator/Rectifier"
and is NOT the same as page 47 "Diode/Rectifier" which I had quoted for you.

This page DOES list OHM ranges for the tests, my apology for mis-leading you


This will, I'm sure, also account for the price difference."
 
"No problem, sounds like I&#39

"No problem, sounds like I've got the same manual as I do.

Wierd that the 75 and 100 have a different, cheaper rectifier... the 8 puts out less power, so I would think that I could probably use the cheaper one. If I have a problem getting a working one from the supplier, I might try that route.

Thanks for the help."
 
"BF100 is rated as 10 Hp motor

"BF100 is rated as 10 Hp motor, but BF8A is rated 8 Hp at the Prop and don't think it would have less thrust.

"Regulator" implies better control of output and it has a graph on page 12 showing up to 5 Amp.

My BF100 will bring back a flat-dead battery enough to electric start my Yamaha 90 within :20 minutes, but see no such graph.

I have also noticed that with a completely full-charge battery, the voltage from BF100 charger can exceed 15 Volts and that is likely what the difference corrects.

Expect you will be best off with the proper unit."
 
"I ordered a replacement, and

"I ordered a replacement, and got it on friday.

Once again, no continuity through the rectifier/regulator anywhere. Checked on another meter, as mine only goes to 2 Mohms, and resistance was in the 3-5 Mohm range.

Hooked it up to a battery, and no current with the engine running.

Anyone got any thoughts? Seems like either the whole lot is bad, or I'm not getting the right part."
 
"Could check for a Ground Faul

"Could check for a Ground Fault, as this is likely most common source of electrical problems.
______________________________________________

Just found a free (PDF) download of BF8D/BF10 Service Manual at this site:

http://novigrad.sitesled.com/honda.html

The top one is about a 25 MB download and goes into more detail than our BF75/BF100/BF8A Honda Shop Manual. Second one is less than 1 MB and bottom one is Owners Manual, also 1 MB.

I know that this is more closely related to the BF9.9/BF15 series,
but you might find some information to help in the large one."
 
"Definitely not a ground fault

"Definitely not a ground fault, as I am doing resistance checks across the rectifier with the rectifier completely disconnected.

I'm suspicious that the problems might be causes due to bad packaging. They just sent it to me in a bubble mailer, and the thing wasn't wrapped seperately. Not sure how fragile these things are, but I imagine a good hit could damage the silicone diodes.

The checks in the manual you linked are the same in my manual. I am reading no continuity across any wires."
 
"These rectifiers are pretty r

"These rectifiers are pretty rugged.
If you are tired of playing with multimeters, reread my prior post...

BTW... That's Robert A. Fierro, BSEE (BS in Electrical Engineering) "
 
"Robert,

My fault for lead

"Robert,

My fault for leading this thread on a wrong path prior to your post:

"...tester with a battery and a lamp..."

Gerry's system (unlike mine) has a "Regulator/Rectifier" (instead of Diode/Rectifier).

Mine was just a Diode test, but his uses a multimeter to test resistance according to the top table on page 16-31 of the Service Manual in the link above. (also posted below, a 29MB PDF Manual)

http://novigrad.sitesled.com/1673.pdf

I only have knowledge of volts, amps, and continuity.

Resistance I can measure, but I am not qualified to advise on it.
"
 
"One of the reasons that I dis

"One of the reasons that I dislike using a multimeter to test diodes in that there no standard in multimeter construction that stipulates that when used as an ohmmeter that there is a + voltage coming OUT of the "Red" ( presumed + lead) of a multimeter. I took a quick look at that table, and its stipulates + leaad and - lead. Which of course all assume that the RED is the +. Not so... In fact the simplest and cheapest implementation of an ohmmeter has a "-" voltage at the RED lead...

In ANY event...while you can use a multimeter to measure a diode/rectifier with some degree of confidence (assuming polarity issues are resolved) Using a multimeter on a REGULATOR is quite problematic. Not all internal circuit nodes in a regulator are accessable via its external leads....

Also, I just did a fast scan of all your posts and unless I missed it, I don't see that you tested to see if anything was coming out of the charging coil into the module. This check should be done with the meter on the AC scale.

mmmmm....BSME.... We had some of them running around the school I went to. The "busting" was merciless. We're talking volts and ohms here, not foot-lbs or psi or even enthalpy :) L.O.L.!!!"
 
"Good info. I've read onl

"Good info. I've read online about checking diodes and multimeters a bit, and got confused pretty quick.

My meter does have a "diode check", and I played with it a bit, even though I'm clueless on what it does (voltage drop across the diode I think?). I'll do that check again tonight, and post a summary.

Even when I reversed the leads though, I still did not get any continuity. I was wondering if 12V had to be on the red and green in order to open a switch or something like that to access the rectifier, but a EE's who I work with say that shouldn't matter. He said the 'regulator' should really only protect against over voltage... not under voltage. Make sense to you? Once circuit class 10 years ago, does not an expert make...

I'm really stumped. I have a hard time accepting that the lot is bad, or that my method is even correct, but I'm at a total loss to explain it. I hooked it up to a battery (granted it was pretty dead at 7V), and go zero current. (granted it should put out up to 5 amps, and my meter only goes to 200mA, but I figure I should have seen something)

I've also borrowed a calibrated meter, so I can at least rule out that.

And I did check the coil, I get contiuity there, and last weekend, I measured AC voltage... about 7-8 VAC at idle, and up to 15 VAC at WOT. Seems to be working fine.

I appreciate the help here. If you ever have mechanical problems in the future, I'd be happy to help.

If I can't figure out somethign different in a day or two, I'm going to return this one, and try to get once from a local honda dealer instead... that way at least I'm dealing with a real person and not an internet company."
 
"Using Fluke 70 DMM calibrated

"Using Fluke 70 DMM calibrated by A2LA certified lab.

+ red lead - black lead
Resistance:
+Red -Green 1.4 Mohms
-Red +Green No continuity
+blu1 -Red No continuity
-blu1 +red 3.47 Mohms
+blu1 -Green No continuity
-blu1 +Green 1.71 Mohms

+blu2 -Red No continuity
-blu2 +red 3.36 Mohms
+blu2 -Green No continuity
-blu2 +Green 1.69 Mohms

-blu1 +blu2 No continuity
+blu1 -blu2 No continuity


Diode checks:
+Red -Green 1.48
-blu1 +red 1.71
-blu1 +Green .50
-blu2 +red 1.71
-blu2 +Green .50

If I'm understanding stuff right, seems like half the diodes are bad, or one side has crappy contacts... probably a manufacturing problem with the whole lot.

Anyone have an idea of where I could find a working one?"
 
"Just a note for anyone lookin

"Just a note for anyone looking at the Service Manual I linked above;
(for a BF8D, not a BF8A) the wire colors are changed on the BF8D:

Blue=Gray and Red=White
_________________________________________________


Also see that where
the BF8A Manual shows >> "Red tester lead"
the BF8D Manual shows >> "Tester (-) probe"

And where
the BF8A Manual shows >> "Black tester lead"
the BF8D Manual shows >> "Tester (+) probe".

Do you suppose they reversed polarity on BF8D's?


Or could one of the Manuals be incorrect?


Other than that, the OHM Meter Test Charts are identical.

The testing instructions are more detailed in the BF8D Manual."
 
"Either way, it's pretty o

"Either way, it's pretty obvious that the two recitifers I've ordered over the past two months are both bad. Seems like bad manufacturing or incorrect diodes..

Anyone got a clue where I might find a good working part, and not the garbage I keep getting?"
 
"Testing a RECTIFIER out of ci

"Testing a RECTIFIER out of circuit with an ohmmeter is doeable.
Checking a RECTIFIER/REGULATOR module out of circuit with an ohmmmeter is...problematic.

Repair manuals traditionally have "ohmmeter" test charts for lots of "electrical stuff". Just because someone took a known working rectifier/regulator module and measured the ohms between various terminals DOES NOT MEAN that those values "hold" for good/bad for all modes of failures. Obviously, if all the terminals on a module read as 10 ohms...then its bad. If all of them read 10 megohms...then its also bad.
I used to own a small R+D plus short run manufacture electronics company and we would design/build somewhat simular circuits (we designed and build all our own power supplies).
ALL of our testing jigs and fixtures sought to evaluate the "real world" performance of everything. TO test this module, we'd hook up the grey wires to a 12 to 24 volt AC transformer, hook up a dummy load (resistor or suitable value) and then read the voltage and current at the dummy load with a multimeter (while we varied the AC voltage... and the value of the dummy load.) That level of testing is beyond the usual mechanic's resources (or patience). In reality, the range of suitable resistances listed in the table for a given test is so wide as to be virtually meaningless.

A quick, no equipment test....

Hook up the module to the motor, gray leads only.
Start the motor, rev it up a bit and using your multimeter on the DC volts scale, read the voltage coming out of the white and green leads.
It should be in the range of 13.5 to 15 volts...

IF that's not possible, hook up the grey leads of the module to the doorbell transformer in your house (24 VAC), read the VDC out of the other two leads. It either outputs enough volts to charge a battery (>13.5VDC) or it doesn't.

A resistance table for a rectifier... OK that makes sense... for a regulator (or anything else with a multiple nodes of active and non-linear(transistors, capacitors and such) devices, it's just a nod to "tradition"..."
 
"I did hook up the rectifier t

"I did hook up the rectifier to the blue leads (grey on other motors), and measured anywhere from .01VDC at idle to .1VDC at WOT.

I'm returning the rectifier today.

Now, the 'OEM' rectifier is about $100... and I know I can get far cheaper ones at radio shack, but they probably won't have the voltage regulator in them. I was thinking about getting a standard rectifier, sealing it all up with heat shrink and potting compound, and trying that.

I have no idea how to build a voltage regulator though... building my own rectifer doesn't seem hard as it's just 4 diodes."
 
Radio Shack does sell diodes w

Radio Shack does sell diodes with rectifiers. I've bought several over the years. Just make sure you get the right size and voltage.
 
"1) A rectifier converts A

"1) A rectifier converts AC to DC
2) A regulator controls or "regulates" the voltage level.

This module consists of 4 diodes in a "bridge" configuration that converts the AC pulses from the flywheel coil to DC pulses. Internally, the regulator circuit takes the DC pulses from the rectifier and limits how high these pulses can be.

My guess...is that in an effort to improve low RPM charging level, HONDA increased the output from the flywheel (the faster it goes, the higher the voltage it produces). They then designed in a regulator function to make sure that the voltage at high RPMs is not too high for the battery.

WD Neal... A diode IS a rectifier... however not all rectifiers are diodes ( there are some pretty elaborate circuits out there that "rectify" and don't have diodes as most folks know them.) Re: size and voltage... I'd get 100 Volt minimum diodes... 200 preferrably.
AS to size... the output as I recall is specified at 5 AMPS... So a 5 AMP diode would work. I'd use a 10 AMP diode. Using any electronic part at its limit is not a recipe for longevity. Now at anything over 1 AMP, one needs to worry about "heat sinking" the diodes.
Soooo, that module is more than just some shrink wrap and potting compound... and since the case of the diode (power diodes) is one of the terminals of the device, unless one builds at least three electrically isolated heat sinks, one needs to mount the diodes to a single heat sink with electrical isolator washers...(its a special kit just for that purpose consisting of a flat "mica" or very thin plastic washer and another one that looks like an "o" ring)"
 
"As mentioned before,testing a

"As mentioned before,testing a rectifer/regulator is "problematic"! It has been my expirence with Honda products, the you should have 17acv at idle and 34+ at higher rpms from the charge coil. Here's a test to do on the charge coil. Check the resistance, then move one of you leads to ground! You should not have a short to ground. A coil can test in ohms spec and fail short to ground test."
 
"I'm not sure if this has

"I'm not sure if this has been tested or not, but if you were to place a small A/C lite bulb across the out put coil and test whether or not the coil will provide enough current to lite the lamp. The discussion has covered the open circuit voltage at idle and at wot, with good results, i,m just wondering if there might still be a problem with the coil.
Nick"
 
"I believe your previous menti

"I believe your previous mentioned voltages are on the low side. Trying the a/c light bulb is a good,simple test,but it will not tell you if the coil is delivering enough voltage."
 
"(I believe your previous

"(I believe your previous mentioned voltages are on the low side. Trying the a/c light bulb is a good,simple test,but it will not tell you if the coil is delivering enough voltage.)

It will if you put a voltmeter across the lamp at the same time.
Nick"
 
"I'm using a calibrated me

"I'm using a calibrated meter, and I get plenty of voltage through the coil. It's also got good continuity, so I doubt I have problems there. I can try a ground resistance check, but that still doesn't answer why the rectifers all have very high resistances across them. Spec says I should get continuity, and I don't get any."
 
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