Topic: Broken down blues - not charging

[Bloody Knuckles]

I've got 72 CB500K1 four that keeps draining the battery while running. Getting about 20-30 minutes max rides out it before it shuts down.  It has a 12v 9amp hour 240 cranking amp 801 Antigravity lithium that tests good, holds a charge on bench, holds charge in bike when key off, has no parasitic drain, but will not increase volts more than a couple hundredths of a volt when revving engine to 5000rpms.

I believe all of my battery tests rules out a battery issue. Plus it has the same issue even with other known good AGM & Li batteries.

I've checked all of the wiring and electrical components for shorts, insulation issues, rusting connectors, loose/bad grounds and bad connections. Nothing found that should draw on the battery only when running.

Plugs and caps good-have spark.

Brand new Rick's R/R which appears to test good. Resistance, continuity, diode tests seem to check out.

Stator appears to check out for resistance, continuity, AC output.

Field coil is where I am not sure if I am checking it correctly. Can anyone provide some guidance  here?

Any other ideas besides field coil? Could stator or regulator/ rectifier be lying to me?

FYI: this is not a stock set up.

Li Battery
LED turn signals and taillight
Halogen headlight
Dyna S ignition
Magna 5 ohm coils with new wires and plug caps
Rick's Motorsports reg/rec for Li batteries
I believe stator and field coil are original.

This is definitely a charging issue, no problems with motor, carb or spark.

Thanks for help in advance.

[newday777]

Welcome aboard the forum
Have you put a volt meter on the battery to test at idle and at 2,500-3,000 rpms?

[newday777]

Here is a thread on testing your field coil

http://forums.sohc4.net/index.php?topic=172358.0

[newday777]

This guy had a bad ground

[calj737]

Your battery is undersized for the stock charging system, and that halogen bulb is also putting a load on your electrical system. These bikes (and their charging system) don’t produce surplus amperage until you’re motor is running above 2,500 RPMs. So, if you are “tooling” around town taking it easy, then you’re depleting the battery almost immediately.

Rev that motor up and keep it running well above 4,000 when you ride. 6,000 RPMs is when the bike comes alive. Lugging the motor at 1,500-3,500 is a surefire way to suck all the juice out of any battery you put in it.

[bryanj]

I have never seen a field or stator go bad electricaly, mechanicaly broken in an accident yes.
Bad charging on a 500 is nearly always the aftermarket reg rec or bad connections.

[Bloody Knuckles]

Newday777, yes, fully charged battery @ 13.87 (with key off) ranges from 13.03 volts at 1000rpms to 13.07 @ 4000rpms- Not much change...should go up to 14.5ish, shouldn't it? That is exactly the charging issue that I am struggling with.

AC stator output is 20v @ 1000rpms, 40v @ 2000, 50ish @ 3000 and 60v @ 4000rpms.

Thanks for field coil check link. I'll take a look at it and see if I am checking it correctly.

[Bloody Knuckles]

Calj737,  I don't know that I totally agree, but see some of your point. The battery is rated for this size bike as long as you don't constantly use it for electric start. Besides, I ran it for several years on the same brand/size battery with no issues. Also, have tried an AGM and acid battery with same charging results. This all started after replacing a previously bad reg/rec.

I can keep the idle high at around 1800rpms, but ride mostly around town, so don't have a bunch of opportunity to keep the revs up while riding unless constantly revving the the motor at stop light...done this and tried riding for half hour keeping it above 3000rpms on higher speed roads...still dies after 20-30 minutes. Same amount of time it takes to kill the battery with just key/lights left on but not running - I tested this. So if there is a draw, it is only when key is on. You might be on to something with the headlight as I've heard this before. What headlight is recommended for these 500s?

[Deltarider]

[...] You might be on to something with the headlight as I've heard this before. What headlight is recommended for these 500s?

This bs is repeated here - and only here - over and over again. In Europe there are no complaints about the CB500/550s charging. Zero! Some models CB500/550 for the European market even came standard with a H4 55/60 Watts headlamp. In addition to that H4, for the last 35 years I have run 3 Ohm coils and yet I have always returned with a better charged battery than I took of with. Where I live, it is not an automatism to use a motor to go places. Common practice is to prefer a bicycle for distances shorter than 5 miles. That halogen bulb is not your problem.

[Kevnz]

I just rebuilt a 500 and as a matter of course, checked the alternator output; the charge voltage only went up to about 12v when revved. All components checked out with a multimeter including the old original regulator. This consists of some points and a coil and the circuit can be traced pretty easily; when the coil operates it shunts excess voltage to ground via a resistor.
In theory, it should have no effect on the charging voltage until it comes into play when the battery is fully charged, but I swapped it out for another standard one and problem fixed. And I agree with Deltarider, I've owned 500s on and off for 50 years and never found the charging system, when working correctly, to be inadequate and I don't go around revving the motor, just ride normally, changing up at 2-3K rpm.

[Bloody Knuckles]

Deltarider, Kevnz,

I think you are right. I double checked the headlamp right quick today to make sure headlamp wasn't replaced with some crazy aftermarket crap bt previous owner. Nope, it is stock. All connection up to snuff and I went through all wiring in bucket again while I was there. Didn't have any issues before, so shouldn't cause any now all of sudden. Also doesn't make sense to have to be winding a motor out to charge the battery. Should do that at normal ride speeds.

[Bloody Knuckles]

I just rebuilt a 500 and as a matter of course, checked the alternator output; the charge voltage only went up to about 12v when revved. All components checked out with a multimeter including the old original regulator. This consists of some points and a coil and the circuit can be traced pretty easily; when the coil operates it shunts excess voltage to ground via a resistor.
In theory, it should have no effect on the charging voltage until it comes into play when the battery is fully charged, but I swapped it out for another standard one and problem fixed.

Kevnz,  Which component did you swap out that fixed the issue - REGULATOR? it is not quite clear to me. If I am reading this correctly, you are speaking of points and coil (within the Vreg). Apologize if i am not understanding fully as I am working with an aftermarket completely encased Vreg/rec combo unit that cannot easily be opened to swap out the guts, uless you are speaking about Ignition coils or battery that was swapped out?

Thanks

[TwoTired]

Did you measure the field coil from the wires that connect to the vreg?  Did you measure 5 ohms?  (Circuit unpowered)

With the circuit powered, did you measure full battery voltage on the same field coil wires? (Alternator not spinning)

Have you confirmed regulator red low resistance connection to battery POS?

Have you confirmed regulator green low resistance connection to battery NEG?

[Bloody Knuckles]

Can someone confirm I am checking the FIELD Coil and stator correctly? Bare with me as I am not a wiring expert - home...pretty good, but motorcycle - still learning. So I may be checking somethings inappropriately (overkill).

With field coil, stator and vreg/rec disconnected from wiring harness and everything:
Multimeter probes between:

Field Coil:

• White wire to frame (clean metal) = 0.00 ohms
  
• Green wire to frame = 4.9 ohms
• Green wire to white wire = 4.9 ohms
  
  Stator side:
  
  
  
  • Between all yellow combinations = .8 ohms
    
  • Red probe to Yellows and Black probe to frame = O.L
    
    • AC output = 20v @ 1000rpms, 40v @ 2000rpms, 50v @ between 3000-4000rpms, 60v @ 5000rpms
      
      Vreg/rectifier:
      
      
      • Between all yellow combinations = 7.9-10.3 Mohms (wowza!)
        
        • Red probe to Yellows and Black probe to ground = 2.5 Mohms (wowza - think this is supposed to be between 5 & 40 ohms)
          
          • Black probe to Yellows and Red probe to ground = 14.5-16 Mohms - reverse bias (wowza!)
            
            • Red probe to Yellows and Black probe to white = 2.5 Mohms (wowza!)
              
              • Black probe to Yellows and Red probe to white = 2.5 Mohms - reverse bias (wowza!)
                
                • White wire to Frame/ground = 8.3 ohms
                  
                • White wire to Green wire = 8.3 ohms
                  
                  • Green wire to frame ground = 0.3 ohms
                    
                    Diode check:
                    
                    black probe on yellow:
                            to ground    to red on reg
                    yel 1      .476          open
                    yel 2      .476          open
                    yel 3      .476          open
                    
                    red probe on yellow:
                            to ground    to red on reg
                    yel 1     open         .476
                    yel 2     open         .476
                    yel 3     open         .476
                    
                    not sure if I am supposed to do this (confused because the aftermarket rectifier has a white wire (not red), regulator has red, but:
                    
                    
                    • black probe on yellows and red probe to whites (+12v) = .48 ohms and red probe on yellows to white = O.L
                      
                      Am I missing something or doing something wrong?
                      Also, starting to question this 9amphr battery even though the last one worked for 2 years no problems.

[Bloody Knuckles]

Did you measure the field coil from the wires that connect to the vreg?  Did you measure 5 ohms?  (Circuit unpowered)

With the circuit powered, did you measure full battery voltage on the same field coil wires? (Alternator not spinning)

Have you confirmed regulator red low resistance connection to battery POS?

Have you confirmed regulator green low resistance connection to battery NEG?

Two Tired, Can you check my last post and provide feedback? or give me more explicit directions for each of your questions? Sorry I am just learning my way around motorcycle wiring & electrics. Appreciate your patience.

[Kevnz]

I swapped out the voltage regulator, mounted under left side cover. It's a pretty simple piece of kit and the coil and resistors all measured correctly, as did the field coil and stator wiring, but just swapping out the reg cured it; 3 spade connectors.
There's good info in the electrical section of the service manual on this site under manuals\ resources. If your reg is a solid state one ( aftermarket) this won't be much use to you, unfortunately. But if your field coil is getting 12v and the 3 stator wires are all within spec, the reg is probably the culprit.

[Bloody Knuckles]

Kevnz, okay...makes sense. I think the idea could apply to my solid state (as far as rectifier side is concerned). I just borrowed an old original stock reg and rec. Going to temporarily wire them up and see if they work. If so, can conclude my solid state reg is bad. Also going to go through all of the multimeter checks again.

[HondaMan]

FYI: this is not a stock set up.
Dyna S ignition

This is where I put my vote...

[TwoTired]

Green wires should have direct connection, zero ohms, to frame and to battery NEG terminal.
The white field wire is used to supply power to the field coil from the regulator.  It should not have zero ohms to frame, unless the vreg is telling the alternator to shut off.

If you are placing probes on white wire and green, 4.9 ohms is fine for an unpowered circuit.  And 12v or battery potential when the circuit is powered And charging enabled.

I’m using Honda diagram color codes. If your regulator does not use the same color code references, you have to translate or tell us what those function assignments are.

The alternator needs the field coil driven with 12v for it to make full output.  If you cannot verify that the vreg is supplying that power on the white field coil wire you can’t expect the alternator to charge the battery.  When the vreg senses the battery is fully charged only then should that white field wire receive less than 12v.

[HondaMan]

I swapped out the voltage regulator, mounted under left side cover. It's a pretty simple piece of kit and the coil and resistors all measured correctly, as did the field coil and stator wiring, but just swapping out the reg cured it; 3 spade connectors.
There's good info in the electrical section of the service manual on this site under manuals\ resources. If your reg is a solid state one ( aftermarket) this won't be much use to you, unfortunately. But if your field coil is getting 12v and the 3 stator wires are all within spec, the reg is probably the culprit.

It is very common today, after these bikes sat unused for a long time, for the silver contacts in the little relay that is the voltage regulator to become oxidized. I clean them with a relay contact file, which is approximately as coarse as 8000 grit emery paper: it polishes them and usually solves the non-zero readings between the contacts when they occur. The silver oxides to a black color, and the contact point is very small.

[Bloody Knuckles]

Hey guys. I know it's been a while, but stopping in to say "we're back in business and on the road again"! After getting the same results with several rounds of entire electrical diagnostics on the whole bike over the last 1 year of piddling with it (stator only at 1/2 the AC output it should, and the R/R failing dynamic tests) and being parked so long without finding reasonably priced replacement parts, I finally just decided to send in my stator, field coil and R/R into Rick's Motorsports and their diagnostics matched mine (so that was a boost of confidence, should done that a year ago) - stator appears as though it was failing after reaching hot temps, field coil re-built because wires had a years of grease/oil/dirt and poor connections and generally worn, and then R/R was passing bench tests but not dynamic tests. Rick's rewound and completely overhauled the stator and field coil and went ahead and replaced the 1 year old solid state R/R for free (since I only bought it a year ago). I received them back on Saturday, hooked it all up and put it back together on Sunday and been out on rides for 2 days without an issue. Battery is now charging again while riding as it should. So good to be back in the saddle. After adjusting the timing to a fully functioning charging system, the bike is running better than ever.

Good luck with your projects!

[Bloody Knuckles]

  Feeling accomplished!

[Kevnz]

Good to hear, congrats.

[newday777]

Feeling accomplished!

Good to hear you are back up and running.
What state are you in??

[Bloody Knuckles]

Feeling accomplished!

Good to hear you are back up and running.
What state are you in??

newday77, I WAS in a state of confusion but now in a state of clarity and bliss! LOL! Seriously, I live in Michigan...fixed just in time to get about a month and half of riding in before it's time to put away the summer sleds and get the winter sleds ready.