Topic: Why do 550's seem to have all the charging system issues???

[Jonesy]

OK, Gang-  I looked through the old posts and found some good stuff, but doesn't completely fit my problems. Soooo...

Background: We've been riding the '78 CB550K and it's been running great, until an electrical bug cropped up. I had to charge the battery back up to full so it would crank the motor (would start fine with the kicker) and I didn't think much of it since I'd been syncing the carbs, making idle adjustments, etc and it had been idling quite a bit. I hooked up the battery charger and let it do it's thing. The battery was still in the bike and connected while on charge.

After charging, we took the bike out for a ride. After about 10 minutes of riding, while stopped at a traffic light, the bike died- no juice. Checked the main fuse and it was pretty warm, but the element was still intact. Hmmm... Closer inspection revealed that the solder holding the element had melted, as a small glob of solidified solder was loose inside. No prob, I figure. The terminals in the fusebox have some corrosion and need cleaning, end of story. I pop in a new fuse and make it home with no issues.

I remove the fusebox and clean all the connections with a wire wheel on a Dremel even though the terminals looked really good. I replaced all the fuses (all correct amperages) with new ones just to be safe. The resistance through the fusebox wiring harness read 0.2 Ohms through each fuse set, so I'm confident that's sorted out. However, after a few more trips on the bike, I feel the fuses after a ride and the main is still noticably warm. I feel around in the electrical compartment to check and damn near burn my hand on the rectifier! I know it's supposed to get hot (hence all the cooling fins on it and it hanging out in the breeze) but is it normal for it to get THAT hot?

This morning I checked things out. I took all the connections apart and cleaned them. I even remove the battery ground wire and wire wheel all the connections until they're shiny. When running the engine, the voltage increases as the RPM's do, but I still check things out:

Field coil- good.
Stator coil- good.
Regulator- good.
Amperage going through main fuse: around 10 amps, high throttle bumps it to 11 amps.
About 2.5 amps through the tail light fuse and about 3.5 through the headlight fuse (I'm running an H4 halogen headlight, all else is stock. The bike has a Dyna-S ignition, too).

This brings us to the rectifier. I tested it according to the Electrics FAQ and got the following results using a Craftsman autoranging digital multimeter:

Red tester lead to green ground lead-
Yellow wire #1: 2.4 MegaOhm
Yellow wire #2: 2.47 MOhm
Yellow wire #3: 2.4 MOhm

Black tester lead to green ground lead-
Yellow wire #1: O/L (On my meter this means open circuit or infinite resistance)
Yellow wire #2: O/L
Yellow wire #3: O/L

Black tester lead to red/white lead-
Yellow wire #1: 1.7 MOhm
Yellow wire #2: 1.74 MOhm
Yellow wire #3: 1.8 MOhm

Red tester lead to red/white lead-
Yellow wire #1: O/L
Yellow wire #2: O/L
Yellow wire #3: O/L

Green lead to black meter lead and red/white lead to red meter lead: O/L
Green lead to red meter lead and red/white lead to black meter lead: 3.7 MOhm

Yellow to yellow: O/L in any combination of the two.

My meter has a diode test funtion, but I could not get any reading no matter how I hooked it up.

Now, here's the funky part: I test ran the bike this morning (I had to adjust the fast idle cam and wanted to check it out) an just ran it enough to warm it up (about 5 minutes). The rectifier got pretty hot after this and the wiring harness off of it was hot too, including the connector block. I pulled the blade terminals out of the block and noticed the green rectifier lead terminal had darkened quite a bit (the way they do when they get too hot at one point). The terminals looked pretty clean on these.. Hmmmm....While the rectifier was still pretty hot to the touch, I rechecked the resistances. They had all dropped a bit, but what really got my attention was that I was now getting a measurable resistances (in the high MOhm ranges, wish I'd written them down..) between the yellow wires. After it cooled off, it went back to the O/L readings. After seeing the darkened green terminal, I checked the resistance between the female recifier terminal and the negative battery terminal and got 0.2 Ohms.

So, my questions are:
-Is this behavior normal for a rectifier? I mean the heat and stuff?
-Is the rectifier toast? (I don't have a Honda manual yet, just the crappy Clymer one that says if any component is suspect in the electrical system to take it to a "qualified repair facility"...)
-If this is normal, is just a matter of the battery not being at full charge? It's a brand new Yuasa battery that I fully charged before I installed it.
-Can I swap out a known good rectifier from my '73 CB750 to test it out?

Sorry for the long post, but when it comes to electrical stuff I don't do so well... (Besides TwoTired will ask all these questions anyway  )

Thanks in advance!

[TwoTired]

Well done Jonsey, I'm impressed!  Lots of meaningful measurements and data.

I've always said that the Cb550's alternator was weaker than the 750s.  And, that higher wattage headlights tax the system.  What wattage did you put in?  I'll need that for calculations.  BTW, you should have increased the fuse rating by the additional current required.

Your rectifier is working fine.  Probably your whole charging system, too.  Hot components and wiring are not a good thing, though.  But, it can be expected when the alternator is putting out full power to both the bike's power consumers AND charging a depleted battery.   If you are trying to charge a depleted battery from the bike's alternator, keep the engine at 3500RPM and pull the headlight fuse while doing so.  If stationary, set up a fan to cool the motor.

When you measured the 0.2 ohms on your fuse clips, did you subtract the meter's test lead resistance?  Because, at 11 amps passing through it, you are dissipating 2.2 volts and 24 watts at your fuse clips as heat.  Also running your fuse at 75% of its rating causes the fuse to run a little warmer towards its melting point.  It dissipates this heat into the fuse clips only when the clips are cooler that the fuse.

If you melted the solder back of the fuse block, did the plastic holder melt, too?  Do the fuse clips still "float" or twist in the holder some?
The design is supposed to allow the clip to self align with the installed fuse in order to maximize surface contact area between fuse and clip.  This reduces the contact resistance.  Also, such heating can remove the temper from the clip material and reduce the spring pressure applied to fuse from clip.  Reduced contact pressure can also reduce contact resistance.

New fuses have a low resistance surface when first made.  However, since they aren't of noble material, they begin to surface oxidize on exposure to atmosphere, even sitting on the shelf.  So, age matters even if they haven't been used.  To minimize contact resistance, polish the fuse end caps. (I like Semichrome and it seems to work well.)  Contact surfaces that look like mirrors is the goal, as that maximizes the contact surface area.  Scratches from wire wheels and sandpaper, leave grooves in the surface, reducing contact area.  It's a nit, but if you want maximum performance and want to operate closer to margins, the nits matter and can reduce contact heating when high currents are passed through them.

Okay, so all these contact issues may be moot, as a fuse running at 75% of rating WILL be warm. My test is that IF I can hold my thumb on the fuse and fuse clips without pain and burning, it's okay.

The Cb550 has a 150 watt rated alternator when the engine turns up to 3500 RPM.  Your 11 Amps through your main is 143 watts (13V system voltage), and 159 watts at the 14.5 volt Full charge on the battery.  This is the power used by the bike.  The charging system is direct connected to the battery.  It is likely your bike's battery will never receive full charge from the bike's alternator as the only time the power is available for charging the battery is when it is depleted.  When the voltage rises, your bike draws more power than the alternator can provide.  Note, this is with the engine reving to 3500 RPM.  Below that and the battery is draining.

What to do?  Reduce your bike's electrical load.   There are hundreds of bullet connectors and contacts throughout the bike.  If each one has an extra .1 ohm resistance, that's 10 ohms, 1.3 amps or about 20 watts wasted as heat and unavailable to charge your battery.  Almost 15% of your alternator power wasted if this is the case.  More if your contact resistances are greater.

You might try this little test to get a feel for the magnitude. Gain access to your headlight connector. With your DMM measure the voltage at the battery terminals; note the voltage.  Now move just your red probe to the headlight connector terminal,  note that voltage.  Lets say you lost 2 Volts.  A 50 watt headlight draws 4.167A @ 12V.  Using this amperage, we know that 8.33 watts were lost in connectors, wiring, etc. between battery and headlight.   And, that the total resistance between battery and headlight is 0.479 ohms.  Looking at the wire diagram I find 17 connectors and switch contacts between battery and headlight terminal.  Simple division says that each connection averages 0.028 ohms in this case.  (pretty good)  If even half the connections were 0.1 ohm instead of 0.028 then 2 amps (26 Watts) is lost to connector oxidation and heating in the headlight wiring alone. That's about 17% of your alternator output.  Lower current circuits won't show this magnitude of losses.  But, it all adds to lost power that could be used to put energy back into the bike's battery.

All this was calculated with two formulas; ohm's law  E=IxR and  P= IxE

If you decide to keep the high power consumption headlight, you might consider cleaning and treating each connector contact in your bike to optimize battery charging.

Hope this helps,

[bill440cars]

         
             Is it possible to increase the output of the charging system? What about the alternator and/or
    components from the CB650 or maybe 750? Just a thought. if the system is prone to problems, is
    there some sort of fix that could be applied? Maybe, except on full restorations, on customs, cafe
    racers, etc there might be better connectors and/or components to boost the system. I'm sure a lot
    of us would like some input on this one. Later on, Bill

[Jonesy]

Well done Jonsey, I'm impressed! Lots of meaningful measurements and data.

Thanks! I did my homework and dug around in the other posts to determine what I needed to scout out first.

I've always said that the Cb550's alternator was weaker than the 750s. And, that higher wattage headlights tax the system. What wattage did you put in?  BTW, you should have increased the fuse rating by the additional current required.

I put in a 60/55W bulb. My 750 never had an issue with it, but after what you said about the alternators this makes sense. I remember you saying in another post something about changing the fuse values to accomdate changes in the electrics. As an experiment, when I rode the bike last night I put a 20 Amp fuse in for the main. It seemed noticeably cooler after the ride.

Your rectifier is working fine. Probably your whole charging system, too. Hot components and wiring are not a good thing, though. But, it can be expected when the alternator is putting out full power to both the bike's power consumers AND charging a depleted battery.

That's a relief! I later found a 550 manual online and it warned against charging the battery while in the bike with anything other than a trickle charger as it could damage the rectifier. But, the battery was sloooowly depleting even before I charged it. The battery was weakend during my morning tests, which probably didn't help in the diagnosis. I put it back on charge to get it back up to full capacity.

When you measured the 0.2 ohms on your fuse clips, did you subtract the meter's test lead resistance?

Nope. And darn it, I've seen you mention that, too!  When I touch the probes together, it dances around between 0.4-0.2-0.1 Ohms. This being said, the fuse box is probably OK in terms of voltage drop, correct?

If you melted the solder back of the fuse block, did the plastic holder melt, too? Do the fuse clips still "float" or twist in the holder some?

The fuse clips themselves weren't harmed. They still can float freely within the holder. Where I saw the solder damage was inside the fuse itself.

To minimize contact resistance, polish the fuse end caps. (I like Semichrome and it seems to work well.) Contact surfaces that look like mirrors is the goal, as that maximizes the contact surface area.

I might give that a try....

Okay, so all these contact issues may be moot, as a fuse running at 75% of rating WILL be warm. My test is that IF I can hold my thumb on the fuse and fuse clips without pain and burning, it's okay.

I can leave my finger on the 15 amp fuse no problem. It's pretty warm, but not burning.

You might try this little test to get a feel for the magnitude. Gain access to your headlight connector. With your DMM measure the voltage at the battery terminals; note the voltage. Now move just your red probe to the headlight connector terminal, note that voltage. Lets say you lost 2 Volts. A 50 watt headlight draws 4.167A @ 12V. Using this amperage, we know that 8.33 watts were lost in connectors, wiring, etc. between battery and headlight. And, that the total resistance between battery and headlight is 0.479 ohms. Looking at the wire diagram I find 17 connectors and switch contacts between battery and headlight terminal. Simple division says that each connection averages 0.028 ohms in this case. (pretty good) If even half the connections were 0.1 ohm instead of 0.028 then 2 amps (26 Watts) is lost to connector oxidation and heating in the headlight wiring alone. That's about 17% of your alternator output. Lower current circuits won't show this magnitude of losses. But, it all adds to lost power that could be used to put energy back into the bike's battery.

Wow! what a good way to assess the situation... I'll try that once the battery is recharged.

If you decide to keep the high power consumption headlight, you might consider cleaning and treating each connector contact in your bike to optimize battery charging.

I have already done this to all the electrics in the charging system, but I'll have to do more...

So, as a test should I maybe fire it up with a charged battery and remove the headlight fuse to see how it behaves? If the wiring is noticably cooler I might have figured out the issue. My wife isn't keen on downgrading back to the original headlight, but I reminded her that she rode around just fine all last year with the dinky headlight on her CB360. It's nice to be able to see better, but you want the bike to have enough juice to get you home!

BTW, what's good for cleaning terminals? Is the spraycan electric terminal cleaner good for the female terminals as they are hard to get any kind of sandpaper or other cleaning method into... I find a scotchbrite pad works good for the male bullet connectors and blade terminals.

Thanks for all of the help so far. It's much appreciated!

[bryanj]

The 500/550 generator is unique the others wont fit, and you dont want a 650 one anyway as they are real #$%*, The most common cause of the green rectifier lead getting hot is the main ground lead not getting good enough contact which means all the starter current goes via the small ground lead at the coils(clean that as well), check the volt drop accross both ends of the ground , there should be no difference ( and volt drop ground lead to engine casing--Generator ground)

[TwoTired]

I put in a 60/55W bulb. As an experiment, when I rode the bike last night I put a 20 Amp fuse in for the main. It seemed noticeably cooler after the ride.
 When I touch the probes together, it dances around between 0.4-0.2-0.1 Ohms. This being said, the fuse box is probably OK in terms of voltage drop, correct?

So, as a test should I maybe fire it up with a charged battery and remove the headlight fuse to see how it behaves?

I think your fuse panel is probably okay.  With the bigger headlight, I'd probably run with the 20A main. In theory, your headlight fuse should also be increased by 1 Amp.  If the fuse clips are working right, they should run cooler.  And, shorts or wiring faults will still blow the fuse with minimal extra strain on the circuit elements.

FYI: The stock headlight is a 50/40.  So, you've diminished the alternator's battery charging capability 15 or 20 watts; about 10%.

Here's another test you can do.  Begin with a fully charged battery and clip your DMM test leads onto the battery.  Remove your headlight fuse and kick start the bike.  Let it idle at 1000 RPM.  If the bike's electrical load exceeds alternator output, the battery voltage will slowly go down.  You can slowly increase the engine RPM and find the point where the alternator output exceeds the electrical load.  At that point, the battery voltage will start to rise as the battery receives charge power.  Note the RPM needed for this to occur.  It will level off when the battery gets fully charged and the regulator turns down the output of the alternator.  The regulator may chatter as it switches the alternator between power settings, so you may not see the full 14.5 volts on the meter.  Plus your DMM has a sample rate where it may miss voltage peaks and valleys.  Anyway, probably 13.8-14.2 volts is where the fully charged battery will appear to stabilize.  Your charging system is working but note at what RPM the alternator makes enough extra power to charge the battery.  Now put your headlight fuse in and repeat the above test.  The RPM "breakeven" point will be higher.  Now you know at what RPM your battery is depleting or charging.  In order to keep the battery charged, you have to operate above that RPM longer than below that RPM.  If the riding style is; start the bike and jump on the open road, you're not likely to notice much of a charge issue.  However, if you are waiting at stop lights more than you are cruising, the battery will eventually not have enough power to fire the spark plugs.   After you clean all the electrical connections, do this test again and grin.

BTW, what's good for cleaning terminals? Is the spray can electric terminal cleaner good for the female terminals as they are hard to get any kind of sandpaper or other cleaning method into... I find a scotchbrite pad works good for the male bullet connectors and blade terminals.

Male terminals you already know how to access and clean.  The female bullets are more interesting.  I made a tool to clean these.  I got a piece of brass tubing from the hardware store in a smaller diameter than the bullet males.  I also bought some crocus or emery cloth.  Very fine abrasive, I think it has a coating of red jewelers polishing rouge on one side.  I used a razor saw to cut a slot in the end of the tubing wide enough to accept the thickness of the cloth. Cut widths of cloth about the length of the bullet male and make the strips long enough to wrap around the end of the tube with the abrasive exposed.  Chuck the tube in your electric drill and insert into the female connector.  As the drill spins it cleans and polishes the contact surface.  You can adjust the number of wraps to make good pressure inside.   If needed, readjust the female socket tension for a good grab onto the cleaned male bullet.  Just before final assembly, I squirt a little DeOxit on both the male and female connectors.
The new tool makes the female bullet contacts easier and faster to clean than the males!

Female spade terminals I clean with a modified thin fingernail file about the same or less thickness than the male spade terminal.  It was well used and not very aggressive cutting.  I ground one so its width was about the same as the male spade.  I made mine cut on extraction from the female spade socket. One or two insertion/extraction cycles is usually all it takes to clean the terminal.   The male terminals are exposed to cleaning like the Bullet type.  A little DeOxit and reassemble.

Hope this helps,

[Jonesy]

Ok, here's an update.

I cleaned all the connections I could easily get to (Being Easter I didn't have plenty of time with family visits, etc) including the ground lug under the tank (as suggested by BryanJ). I ran a few more tests and the results were as follows:

Ran bike with fully charged battery and no headlight fuse. The main fuse (15A) felt to be pretty much the same temperature (read= did not get hotter), the rectifier was pretty warm.

I put the 7A headlight fuse back in and reinstalled the stock headlight (to eliminate a variable). When running, the voltage at the battery gradually dropped, as expected. However, the voltage seems proportional to the RPM's. It seems to hit a peak at 4,000 RPM at about 15.5 Volts. After that, as the RPM's go higher, the battery voltage slowly declines. As before, the rectifier and it's little wiring harness were quite hot.

I also put my ammeter between the positive battery terminal and the positive battery cable. At idle with everything operatinf normall on the bike, the battery has a net loss of around 7 Amps.  This is close to the value of 6.5 shown in the manual. At around 3000 RPM, the net gain/loss is 0 Amps. After this, higher RPM's only give higher net gain amperages, getting as high as 4 Amps going into the battery at 6,000 RPM. If the voltages were higher, the amps (in theory) should go down to keep the same wattage, according to Ohm's law. It looks to be following the law as above 3000 RPM (when the charging system kicks in) I am seeing a rise in output current while seeing a decline in output voltage.

This just doesn't seem right. It doesn't agree with the charts in the manual. The voltage should top off at 14.5 Volts beyond 4,000 RPM and the amps should drop off beyond this point.

Any ideas? Is it possible for me to swap the known good rectifier and regulator out of my 750 and test it with those?

[dave550K]

Thanks for al the good help. I was actually looking for help with the rectifier on a 78 550K today as well. I am having a similar problem, where the battery does not charge. I also did the rpm test and got around 15V (analog meter), but the battery does not charge. I am working on my brother-in-laws bike, and I am stuck. So after figuring the charging system was good I started checking elsewhere. I first took off the positive lead of the battery and measured its resistance to ground. It is 10 ohms. I traced where the ten ohms is coming from to the rectifier. If you read across the red and green with the red test lead on the red, there is 10 ohms between them ( and open when polarity is switched). Is this wrong? I am sorry to jump in the middle of your discussion but I just saw this and figured you guys could help. Thanks,
Dave

[dave550K]

Ok, so I checked the ohm readings again, and I found out my meter can't be trusted.. When I changed between R*100 R*10 and R*1 they all give me different readings. So I will go buy a new meter and get back. I need a DMM any way. Also I am thinking the whole problem could be city driving, and he will just need to charge the battery regularly. Is this a common solution? Thanks again,
Dave

[Jonesy]

When I changed between R*100 R*10 and R*1 they all give me different readings.

Are you reading the appropriate scale for the particular Rx socket you are using? It should give you different readings.. the numbers are the multiplier for a particular scale on the meter as a meter scale will only give you so much resolution. It's been awhile since I've used an analog VOM, but I think the Rx1 reads 0-10 Ohms, Rx10 reads 10-100 Ohms and Rx100 reads 100-infinite Ohms. (Hope I explained it right!)

[TwoTired]

It seems to hit a peak at 4,000 RPM at about 15.5 Volts. After that, as the RPM's go higher, the battery voltage slowly declines. As before, the rectifier and it's little wiring harness were quite hot.

This just doesn't seem right. It doesn't agree with the charts in the manual. The voltage should top off at 14.5 Volts beyond 4,000 RPM and the amps should drop off beyond this point.

Any ideas? Is it possible for me to swap the known good rectifier and regulator out of my 750 and test it with those?

You're right on track.  Your regulator isn't doing its job.  When the battery peaks at 14.5v the regulator is supposed to turn down the power output of the alternator.  It isn't, and is why the rectifier is hot all the time, dumping all that energy into and over charging the battery. The battery life will shorten, by the way.

Check the voltage at the regulator's terminals, engine running.  When the Black and Green is where the regulator monitors the battery voltage.  When it gets to 14.5 or 15V, the white terminal should drop from whatever is on the black wire to about 8.5 V.   This lowers the field current, reducing the magnetic field, and thereby the output of the alternator.   If that isn't happening, pop off the regulator cover.  The white wire should drop to zero when you mash your thumb on the little relay top.  The white wire should go to about 8-9 volts (it's proportional to the black wire voltage), if you can manage to hold the moving contact so it neither contacts the upper or lower contact.  It's possible someone has gotten in there and tweaked it out of proper adjustment trying to compensate for all the things you've now fixed on the bike.

I believe the 750s regulator is interchangeable.  If you want to try that.

You're doing good work, by the way.  You're almost there.

Cheers,

[Jonesy]

Well, after an afternoon of humming "Take this bike and shove it", I MIGHT be on to what's going on. Here's the latest in the 550 charging system saga:

After TwoTired's outline above, I was all excited figuring I could swap out the reculator and the problem would be solved. Ha! I removed the cover off the 750's regulator and fired it up. As the RPM's climbed, I saw the movable contact slowly shift from the upper terminal (full battery voltage to the field coil) to the lower terminal (battery voltage reduced by a 10 Ohm resistor) and noted the corresponding change in charging voltage. OK, now I've seen the system in action and understand a bit more of what's going on. So, I put the 550's regulator in the 750 and fire it up. I rev up the throttle and look for movement at the contacts... nothing. So, I figure it's a bad regulator.

But, to be sure I install the 750's regulator into the 550 and fire it up to see what happens... NOTHING! The known good regulator behaved like the bad one. I start comparing the stats on the regulators, thinking maybe the 750 regulator is different from the 550. The stats according to the Honda service manuals were exactly the same. I check both units and the resistances for the engagement coil and resistors are the same. Hmmm... According to the bench tests, all the components of the system are OK. So, I tried a few dynamic tests, at the suggestion of Oldfart...

I turn on the igniton and I get a strong magnetic field at the alternator housing. Then, I depress the regulator contacts and the field gets weaker. I also start up the bike and move the contacts again. The system voltage drops and the RPM's climb, as the the alternator has less of a magnetic field to slow the engine at idle (and energy to pump into the system). The circuits themselves are working. Hmmm... I rev up the bike and notice something happening at the regulator at high RPM's: with the garage getting dim as the sun went down, at the point the measured battery voltage was hitting around 15.6 volts, I saw faint arcing at the upper regulator contact. At even higher RPM (around 6000) the arcing stopped, and the voltage began to go down. The regulator is trying to do something, but seems to be having a very tough time doing it. Closer inspection of the regulator (the one that was in the 550 originally) revealed lots of pitting and blackening, like a set of breaker points after it's condenser went bad. It doesn't seem to be getting enough juice soon enough to generate enough of a magnetic field to pull the contact arm.

So, the triggering black wire that the regulator uses to reference system voltage must have some issue. I rig up a jumper wire to the voltmeter as the terminals on the bottom of the regulator are buried behind it when mounted on the bike. (I originally wanted to wire the black terminal of the regulator directly to the positive battery terminal and monitor the amps, but my ammeter kept beeping in protest that I was going to blow it up if I left it connected, so I couldn't try to bypass all the other junk in the electrical system..) I fired it up with a voltmeter monitoring the voltage at the black regulator terminal. I rev the bike up to the point where I was seeing maximum voltage at the battery (and the arcing at the regulator contacts) and noted the voltage seen by the regulator, referenced to the negative battery terminal. The regulator was seeing 2 volts less than the battery! So when the battery was seeing 15.5 volts, the regulator was only "thinking" it was seeing 13.5 volts... A-Ha! I was told a 1 Volt drop between the two was normal, figuring the resistances of the connections, key switch, etc. This was double that. If it was only a one volt difference, the regulator would "see" 14.5 volts and know it was time to kick the alternator into low gear...

The red paint was still intact on the regulator spring adjustment screw, so I doubt it had ever been messed with. At least I think I have a handle on the problem now. Hopefully tomorrow I can see what I can do to resolve it....

[Bob Wessner]

Hey Dan,

Since my eyes glaze over at the mere sight of a wiring diagram, should I ever have an electrical issue, you just may be getting a phone call. 

[TwoTired]

So, where did I go wrong with instructions?

I thought measuring the volts at the regulator would isolate a bike wiring issue from a faulty component.

How should I have written the instructions to be clearer?



 

[Jonesy]

You're instructions were fine. (I know.. I was doing so well up to this point..) I was frustrated as nothing blatantly wrong was showing up. I think the main difference is that the first time I did it, I was comparing the voltages at the regulator, just assuming that's what the battery was reading. It's when I compared the values to the battery itself that I began to see the problem. The regulator was making the voltage shift.

Part of it is that fact that the 550's regulator is tucked in behind the electrical tray and the wiring to it is so short that it cannot be pulled out for easy access for testing. the other part of this is my uneasiness with dealing with electrical problems. I tend to look for the "silver bullet" solution rather than have the patience to work through it and most of this stems from my lack of knowledge. Doing the stuff I did in the latest post was probably not all that productive, but by going through it I gained a much more intimate knowledge of my bike's charging system. I find that once I know something inside and out, the problem becomes much more rational and easier to attack logically. I guess that's why I'm more comfortable with doing engine rebuilds than electrical troubleshooting. Worn engine parts show themselves readily, either by sound or apparent wear. Electrical issues are more mysterious. Bad parts can look just like new ones. I think part of it was I latched on to your sentace that the regulator wasn't doing it's job. You gave me a target to shoot the gun at, and it narrowed my thinking.

So, should I keep poking around to see if I can find any wiring issues (this was another frustrating part as aside from a handfull of corroded terminals, all the rest of them look great)? Should I start thinking about adjusting the regulator?

Since my eyes glaze over at the mere sight of a wiring diagram, should I ever have an electrical issue, you just may be getting a phone call.

I don't think you could afford it, Bob....

[TwoTired]

Okay, here was my thinking,  You had already established that the battery was getting to 15.5V or higher.  The regulator's job is to keep it below 14.5V.  That's why I had you measure the V at the regulator terminals; to find out on what basis it was making its decisions.  Basically, the bike is lying to the regulator about the battery voltage so it can't do its job.  I thought you'd notice the voltage difference from that of the battery right away.

So, what to do now?  You COULD readjust the regulator to compensate for the voltage loss.  It's something I might do if I was away from my garage and tools.  But, this is just a band aid.  Whatever, has deteriorated on the bike to lose the voltage, will likely continue to do so.  How often will you monitor the situation for the next re-adjustment?  The deterioration is probably losing power by heating someting up that shouldn't be.  And, if the cause fails outright and it gets fixed with a repair, will your remember to go back a readjust the regulator before the battery goes dead?
 Were I you, I would track down the cause of the voltage loss and eliminate the guilty party.  Then there won't be a need to readjust the regulator.  And, you might get to use your brighter headlight after all.

The black wires are a +12V buss activated by the ignition switch.  If that's two volts down, a lot of things are not getting full power.  You might measure random black wires on the bike to verify it is a systemic problem.

Here's a trouble shooting technique:
Get or make yourself a meter probe with a fine pin point or clamp a pin or needle to your existing probe.  You can use this new probe to pierce the wire insulation for voltage readings in circuit.
You can do the following tests without the engine running.  However, it is helpful if you can maintain a consistent voltage at the battery. Take out the headlight fuse and put the battery charger on it to help keep the voltage constant.

Clamp one meter probe to battery minus.  And, with your pin point probe, compare the voltage readings at or near the regulator black connection with the battery post.  Refer to your schematic.  Note there is a connector block between the regulator and the ignition switch.  Measure the voltage of the wire on each side of the connector block.  Next measure the black wire voltage at or near the ignition switch.  The ignition switch is supplied power by a red wire.  Measure the Red wire at or near the ign switch.  You should be writing these voltages down, by the way.  The red wire goes to the fuse block, but goes through an inline connector before doing so.  Measure the red wire going into the connector and coming out.  There are four of them so pick an inline pair. The other pair is the supply to the fuse.  Measure those two also.  Note you are working back toward the battery and the voltages should become closer to what is at the battery, the closer you get to it.  The red wire goes through another connector block, again measure on each side) before attaching to the big red battery cable at the solenoid.  (I've seen this ring lugs corrode at the crimp).  The big battery cable ought to have the same voltage reading at each end of it.

If you haven't found a big voltage loss along the route while probing, then look at your data list.  Go after the terminals or contacts with the biggest numbers. And you will likely find problems there.  Could be connector contacts or the crimps onto the lugs for the contacts.

Any questions?

Cheers,

[Jonesy]

No questions, clear as glass!

Thanks for taking the time to lay it out. I had already formulated a plan of attack similar to what you described, tracing out the voltages. As for noticing the difference from battery voltage, I was never sure what it really was, as I'd be constantly stopping and starting the bike to do different tests, with my meter connected elsewhere. This is why I really like your idea of a battery charger on the bike to keep the voltage constant!

Corrosion at the crimps in ring terminals, huh? I'd bet my lunch that's part of the issue, as both ends of the main ground lead (battery and case connections) are dark green the crimp, and at the positive terminal, too as these are exposed to the elements. Come to think of it, I remember wondering to myself if this corrosion had any effect on the current through the terminal itself. Now that I know better, I realize "DUH!".. I'm probably limping right out of the gate. I just figured well, everything's working, so it can't be a bad ground. This probably explains why when I did your headlight bucket voltage test, I got 2 volts lower than the battery. I overlooked the obvious.  I'll verify this with the meter tomorrow.

It all seems so simple once you know what's going on. But, I have learned a great deal from this experience and don't feel so intimidated by electrical work (of course, this will be more true once I know I've licked this issue!).

Thanks for your help and patience!

[Jonesy]

OK, I think we're pretty close. I did the sytematic voltage drop test and discovered a slight drop at the fuse panel, the main wiring harness/electrical tray connector and the biggest was a 3/4 volt drop at the ignition switch. I took everything apart and polished the terminals to within an inch of their lives. The switch terminals were a dark bronze color, so no wonder they were causing a problem. After all this, I'm now seeing only a 0.9 Volt discrepancy between the battery and the black regulator wire (was 2 volts before). I'll probably go ahead and make new battery cables to be sure I'm not getting any blockages there, too.

The voltages look better at the battery, with only a small spike to 15 volts around 4,200 (you have to hit it just right) but it lowers to 14.5-14.0 thereafter. The amperage to the battery seems more under control as well, only peaking at 4 amps just as the alternator really kicks in around 2500 RPM. After that it hangs out in the lower ranges. Still not textbook perfect, but a marked improvement.

So, I'll continue to keep an eye on things, but I'm cautiously optomisitc that I improved the electrical behavior. Let's keep out fingers crossed...

Thanks again for all the help, TwoTired!

[wardmoto]

awesome example of the power of this forum...kudos to you both for taking the time and sharing.  I read every word and visualized every test you guys spoke about.  Peoples dislike for electrics comes from not understanding.  I am new to this forum, but two tired deserves a round of applause for even taking the time to bother.  Reminds me of TLRman on my suzuki SV forum.Really great job guys, thanks  Bryan

[HondaMan]

Umm..not to be snotty...this is the Electrical Engineer speaking...(tap on the microphone)...

The regulator may not pull down from high current charge mode to low current maintenance mode if the ground for the coil has bad contact to the frame. How it works: When the battery voltage rises enough to pull in this relay, the current from the alternator drops because resistance is connected to the field for the alternator. When the voltage falls down again, this relay relaxes and the contacts kick the alternator into high gear (the default condition) again. A bad ground for the regulator's coil will cause the 14.5 volts you see, and is the reason the subbed-in 750 regulator didn't work, either.

Check the ground lead from the regulator to the frame. Clean the contact and put a drop of oil on it before tightening it back down. If you have a wiring harness connection to this point, trce it back and find the guilty connector.

Quarter car washes are the regulator's enemy. The alkaline soap is good for grease removal, bad for electrical contacts. That's where this usually comes from, and it so happens that the 500/550 grounds are right where you would spray...   

OK. Mike's off....