Charging system

Since i had this bike i have been plagued with batteries not charging. I changed the regulator, checked the stator core and all is in spec. The stator on the other hand is giving me 2 to 3 oems should be 4 to 5. Would that be the charging issue? A spare one i have is giving me the same read out.

When i do a voltage check during start up my volts are 13 and at 2500 rpms the volts dont change. Checked the brushes and they are brand new. Not sure if its the stator or if something is wired wrong.

The red wire coming off the regulator is connected to the positive battery terminal. Brushes are goinv to the regulator.

Any advice?

 

Took the bike out to test the changes i did to the carb. Made sure the battery was fully charged. Got about 1/4 mile and poof bike died. The battery was completely dead. The battery shouldn't have drained so quickly.

The rectifier is wired per factory specs. Wonder is there is a short some place draining the battery.

 

Brushes are good but are communicator rings clean along with all connections. Should be a connector with 3 white wires coming out of alternator. Those are the output wires which is AC volts. Check voltage of all three to see if you have a weak or bad leg coming out 13-14v AC? Again check all connections are clean and tight. Extra ohms make heat which makes magic white smoke.

 

Did all that. The stator wires arent putting out a current. I just ordered a new stator from ricksmotosports.

I also cleaned and inspected everything. If this doesnt work than.... i think i give up.

 

I understand your frustrations. Do you have a wiring diagram?. What is the bike. Looking at my 650 diagram should be constant 12v on brown wire. Green must be variable ground.

 

The 3 wire 3 phase stator (stationary) should read .46 ohms between each leg. Also, no leg should have continuity to ground. If you get the correct reading on the stator (usually reads a bit high because of the DMM lead resistance and not a perfect contact with the terminals), then it should be OK and just needs a rotating magnetic field from the field coil to produce a voltage. The AC voltage output from the stator is rectified by Rect section of the Rect / Reg and applied to the battery to charge it.

The field coil (rotor / electro magnet) should be 4 ohms +/- 10% when measuring at the copper rings. Theoretically, it should be the same at the two pin connector for the brushes, but will often read a bit higher, like in the 10 to 15 ohm range. Current through the rotor that travels via the brushes is controlled by the Reg section of the Rect / Reg. When you turn the key on the regulator should provide maximum current through the rotor as the motor is not spinning and thus there is no output voltage. You can do a quick check of the magnetic field by holding a thin feeler gauge about a 1/4 inch from the AC Generator cover and turn on the key. If a magnetic field is being produced ( Reg sinking current through the rotor/ brushes), then the feeler gauge will be pulled toward the cover.

It is hard to keep up with everyone's individual bike, but does this imply some re-wiring was done? If so, then yes a point to point continuity test should be done to be sure all connections are present and going to the correct place.

Detailed instructions per the service manual:

Note also battery condition is very important, always start with a fully charged / tested battery.

 

Thanks, but i tested all of that, which leads me to think the stator is dead. Since the oems i am getting is .2 and no power is coming off it while running.

 

Well, one of these statements is not correct, but hopefully you are on the right track. The reading of .2 for the stator is quite a bit out of spec (.46 +/- 10%), especially considering a standard DMM is going to read a bit high typically.

If you want to share what you got for "that" then perhaps some other advice could be given. I tend to be a bit anal about testing and verifying why and what part is bad, sometimes it is quicker and easier just to use the shotgun approach. If the stator is indeed .2 ohms between the white wires, then good call ordering one.

Very true if the battery is OK. Do you notice any small sparks when connecting the battery with the key off?

I think I remember you going through all sorts of issues getting the motor squared away. I remember thinking you don't have give up in you and I was really impressed with your tenacity.

 

+1 to that ^^^

 

Thanks guy. Means a lot.

Regulator diode test passed with flying colors. Dc volts test coming out of the brushes Green and Brown wires + black ground passed. Green was like 14 volts. Brown i dont recall.

The stator oems came up as .2 ohms all 3 wire combo testing.

The rotor core was 4 ohms and was in spec.

Ran the bike and tested the volts coming out of the stator and 0 volts. Tested all 3 wire combos. Shut the bike off and tested ground and it passed.

I have a new stator coming in the mail hopefully this will resolve the issue. The only thing that isnt new after this will be the pumpkin. Everything else has been rebuilt or bought new.

 

That's the V2 voltage in the service manual Rect/Reg diagnostic instructions. It should be:

"Turn the main switch on. Make sure V2 is less than 1.8V"

A reading of less than 1.8V indicates maximum current through the rotor for maximum magnetic field strength. The Reg section of the Rect/Reg controls this line and is pulling it low with the engine not running as it is sensing a low output and increasing the current / magnetic field to attempt to increase the voltage output from the stator.

The stator condition will not affect the reading for this test.

Also, 14V would be unusually high. Are you using a DMM (Digital Multimeter) or VOM with a moving pointer?

Was a battery charger hooked up when the measurements were made? The test should be done with a fully charged functional battery, no charger connected. If a high output battery charger was connected during the test, it could conceivably affect the V2 reading by raising battery voltage enough that the regulator throttles back a bit by raising V2.

 

I am back in new jersey working on the bike. When i redid v1 and v2 the numbers were different. V2 didnt even register on my digital meter. V1 when running was around 4.5. The book says it should be around 14.5 volts.

Ran the bike with the new stator and nithing no charging. Is this a sign its the core or possibly bad brushes?

 

You mentioned earlier that the field coil measured 4 ohms so that should be good. You need to measure the resistance at the 2 pin connector with everything assembled. Theoretically, it should measure 4 ohms, but 10 to 15 at the connector is usually OK. Also, check the pins to ground to be sure there are no pinched wires.

V1 should be very close to battery voltage and is the output of the ignition switch that goes to numerous locations, such as the input to the signal, head, and ignition fuse, along with power to the brushes and as feedback to the regulator to determine if more or less field current is required. It is spec'd at 14.5 when revving the bike to 2K plus as it should be equal to battery voltage.

You don't need the bike running to evaluate if V1 is totally screwed for some reason. With the key on it and the bike not running V1 should be near 12V with a fully charged battery. If it is indeed really low like the 4.5V then check power at another location, like the signal, ignition, or head fuse. If it is OK in other locations, check at the 2 pin brush connector on the brown wire, that should also be switched battery voltage.

Hopefully this is because V1 is so far off that the Reg is pulling that point low. However, if V1 checks out as OK then there are several reasons V2 would be absent:

Power to the brushes is missing or the brushes are not making contact with the field coil slip rings creating an open circuit.

A wire is pinched causing loss of power or applying a ground

The power device within the regulator is shorted pulling that point to ground. This one is not likely as it would cause an overvoltage condition, the opposite of what you have.

This should really be wired per the print, where the red wire goes to the output of the main fuse. If the diodes within the Rect/Reg assembly were to short, a catastrophic failure could occur from the absence of the fuse.

 

I ended up rechecking all my connections and found a few places where i used the original connectors. I decided to rewire and use new fresh connectors, it made a difference. When i tested v2 again it was at 9 to 10 volts. The battery at the time was at 11.75 volts. I have it recharging atm.

The weird part is when i tested v1 black and green, it showed the same voltage.

 

V1 should be black and brown. There are service manuals out there that have V1 and V2 reversed, like the Haynes manual and the XJ750RH Service Manual that I have. The excerpt above is correct and complements of Jayrodoh - not sure which book he has.

 

I am waide

 

I am beside myself not only can i not replicate the numbers from lastnight. I the bike still wont charge. I am going to order new brushes and see if that helps.

Dont know what else it could be. Core checks out, stator is new, rectifier is new and all diodes are working.

 

Anyone near the littlegg harbor new jersey that wants to help me figure his out.

 

Did you do a continuity check at the brush 2 pin connector?

What is your current reading on V2, the black to green wire with the bike not running? It should be below 1.8 V, but not zero.

And, may as well include your latest V1, the black to brown just for the info. It should be close to battery voltage.

 

Not sure if i am doing it right so i made a few videos.

Videos of me testing

https://www.flickr.com/photos/tbran/33960888204/

 

Continuity on brushes beeps with a 6.8 reading.

Black and green no power reads 0

Black and brown reads 4 volts

 

That's a good reading if done at the 2 pin connector. Did you remember to check them to ground also.

Check the voltage at the 2 pin brush connector with everything connected bike not running key on. Brown for battery voltage input to field coil. Green for output of field coil to regulator. Either the input power is missing to the brushes or there is an open in the green wire at the 2 pin brush connector to the Rec/Reg. Assuming regulator is good and no pinched wires.

 

Didn't see that, but not good. So, open or resistive line in brown wire to regulator, or poor ground for the regulator.

I sent you a PM

 

I did not, i didnt think of it.

When i tested the regulator; white, red and black diodes passed. When i connected ground/black wire to the green and brown it failed and gave me a read out. Didnt test with positive/red wire.

I hope its not the regulator but at the same time if that is the issue then i just want it fixed. All of the reading i get aren't consistent and i can never repeat to get the same numbers eg, last night i was getting good numbers for v1 and v2 and this morning i got crap. The only different was me recharging the battery and moving it.

The way i have the rectifier grounded is directly to battery. would this be the issue? should i have it go to a frame mount instead? The ground wires i have going to the battery are 3; Regulator, frame and i dont remember the third. Could this be the issue?

Here is an after thought, looking at the xj650 wire harness, and xj550 just cause its interactive http://lumien.se/stuff/xj550/XJ550ElectricalDiagram.html. I am starting to think the regulator isn't wire up properly. The only wires going to the regulator outside of the stater and brushes are the red connected to the battery and the black to battery ground. Should there be power going into the regulator via the brown wire and splitting into the brushes?

 

If I read this right you are OK here. The diodes are checked using the Red to White and Black to White and you got a pass there. Black to the green and brown could be useful info, but it is not part of the testing procedure per the FSM.

Electrically that should work, but the frame would be a better location just to reduce the number of terminals on the battery and to stay away from the corrosion that can occur on the post. If moved to the frame, just be sure it is an unpainted clean surface, and that the motor to frame grounds are present and clean.

Absolutely a must, and this is likely your whole problem. You must have the switched power (from the ignition switch) going to the brown wire on the brushes and also to the regulator. The feed to the brushes provides the power to the field coil to create the magnetic field that when rotating induces the voltage in the stator. The feed to the regulator is the sense line, and is monitored to regulate the voltage out of the stator by adjusting the current in the field coil by varying the voltage at the green wire.

 

I feel like an idiot that i never wired it up. Live and learn. Now i gotta rewire the aux output. Might use the opportunity to clean up the wiring more. Not sure i like having a 1 to 3 connector with bullet plugs. Might look for another solution.

 

So, buried within the harness Yamaha did not give it much thought on doing splices. They simply used a crimp and in this case went from 1 to 5 connections and covered it in electrical tape. Good for 35 years and still going strong.

 

I tried to stay away from that as i wanted the entire system to be setup as plug and play. I actually ended up using Female Triple Bullet Terminals throughout the bike. However it does complicate things and take up space which is bad, especially the way everything is wired already, I cant give up any more space.

 

Hey sybe, I know this is Hella old, but did you ever figure this out? I'm plagued with the exact same problem and this bike is my only transpo. Which is cool coz its a cafe but its dying everywhere and killing me! Thanks in advance.

 

Please start a thread for your machine so we can focus on your particular problem. Similar symptoms do not equate to the same fix.