Hello everyone. This has been an ongoing issue for me and I have yet to resolve it. At first I thought the bike was no longer charging the battery because the Voltage Regulator red wire was frayed due to rubbing against the air box and sub frame. Anyways, the wire has been fixed and I have done AC reading tests for stator output which yields steady AC volt increase up until a max of 110 ac volts at 8000+ rpm. The stator is also getting proper readings as described in the maintenance manual. Battery is brand new. Also, as of this writing, I received a brand new voltage regulator, plugged it in and tested the bike for charging with no success. I have also tested positive battery wire and regulator red wire continuity and it has passed at 0.2 ohms. Clearly there is an issue but at this point it is difficult to identify. Hopefully it is a small fix but at this point any possible solution is beyond me. I hate to give it to a mechanic to troubleshoot but it may have to be done. If anyone has experienced such an issue; may have a possible solution; or may have some technical knowledge to share, please let me know.
So you have three wires with AC coming into the VR (yellow wires, probed right at the plug) but no charging voltage on the red wire right at the VR (13+ volts, bike running)? Have you confirmed the blue wire has continuity to battery negative and motor? .
My findings as of today: Red wire (pin 5 on the voltage regulator xonnector) has 12 volts+ with the bike off but fully connected. It drops to around 11.5 volts and stays there with the bike running. I am suspecting that the starter relay is not conducting. As per wiring schematic, rectified voltage travels through starter relay before it gets to battery. Obviously there is a problem between the VR and the battery. The only part between these two is the SR
Also I have .3 ohms continuity from blue VR cable to negative terminal on battery. I've also tested continuity from red VR cable to positive battery terminal it's .2 ohms. The only discrepancy I can find is with the problem above. Do I need a new starter relay?! Please let me know.
The starter relay is only a common point but you could measure the ohms from the red wire at the white connector to the battery terminal on the SR, just to make sure there is nothing wrong with the white connector. The red wire from the VR joins the small red wire at the starter relay white connector, through 1 of the 20A fuses (Brake side fuse is a spare) and then to the + battery lead. From your post I think you have the circuit idea backwards. The VR will always have +12V with the bike off since it is connected to the battery. Once running the VR voltage should be higher than the battery voltage so it charges. I think your starter relay is fine - it acts as a connection point and fuse holder only for this circuit in question. I had a similar issue and it was the fuse being weird. Replaced the fuse and my intermittent no charge vanished. It may be that you have a partial short in the red VR wire before it gets to the starter relay. This could bleed off voltage (high resistance) in parallel before it gets to your battery. A check to do is: bike not running VR unplugged, +battery terminal disconnected, measure red wire to ground. You should have infinite ohms. Let me know how you make out. I have my VR apart right now to modify it for longevity. 3 things I am doing: adding flat aluminum heatsink to back of VR - my VR makes almost no contact with my frame. Dedicated ground strap from VR ground to engine ground (or battery -). Tomorrow I am upgrading the VR red wire to #10 and it will go direct to the + battery terminal with a 30A fuse. These are very common mods for any bike VR to keep it alive. Heat and poor connections are the enemy. I will also crimp the VR terminals for a tighter fit. Hope this helps. Cam. PS the starter relay closes only to turn the starter motor. All it does.
For the white connector test I am getting .2 ohms. For the second red wire to ground test with battery positive disconnected I am getting no reading at all. The meter is not registering anything...Does this signify infinite ohms? The red VR wire was shorted when half of the strands were chewed through due to rubbing against the frame/air box. This has since been fixed professionally but I have not yet verified the work. I'm assuming it was repaired correctly...let me know what my test findings signify. Please and thanks.
Fingers crossed but it seems like my stator is good. I have done the tests outlined in the maintenance manual and measured ac volts going to the VR connector yellow wires...all 3 are getting the same voltage at idle 24 ac volts. This steadily increases as rpms grow. Im assuming there is no limiter on the amount of ac output from the stator it all depends on rpm. Cam, could you please let me know what your bike is getting at idle so I can cross reference and maybe identify an issue.
I think mine was getting 25VAC at idle. I think you have to take the VR plug off to measure the higher openloop voltages speced in the manual. The results of your tests are good. The limiter on the AC output is the magnetic saturation of the stator coils. I am assuming that your root problem is that the battery is not charging. What is the battery voltage at idle? You should also try the original VR. It is possible that you fixed the problem (wires) and then swapped in a bad (new) VR. It happens. I wonder if your battery is bad. Its rare but does happen. Can you disconnect and test with another. Even a car battery. We should be able to figure this out. Cam.
The battery is a brand new yuasa. I have only plugged it into the bike for testing purposes since I got it 2 months ago. I now have 3 VR'S...I will test each and every one and get back to you once I install the new SR. Thanks for your help thus far. Alex
I can try probing the battery only and see what voltage its getting but last time I did it it was only 12.4 volts...does not increase at all while bike is running at idle or with revs increased. I even tried this test with a brand new Voltage Regulator which suggests it is not the VR...stator has passed all tests (apparently could still be bad?) The maintenance manual lists the starter solenoid (relay) as part of the charging system so that is why I ordered a new one. I can try a new 20A fuse and see what that does, it worked for you it may work for me as well. Other than that I'm stumped. All I can do is check connections/grounds once more and enlist the help of a mechanic as a last resort. My dealer technician suggested that the stator could be sending too much ac voltage to the VR which causes it to shut down and therfore does not send charging voltage to battery. Does this have any truth to it? Like I said, idle ac voltage is 24. I get a maximum of about 100 if I really rev the bike to around red line.
Keep testing the battery voltage while running. It will tell you when you have fixed the problem. It what the dealer tech said was correct then your bike would charge at low speed and not charge at high rpm. I don't think that's the case. The 20A fuse is worth trying. Here is a good diagnostic chart from electrosport. Does the battery have a good solid ground wire to the engine? Cam.
The DC voltage readings you're getting right at the regulator (red wire) tell me there's nothing wrong between there and the battery (if fuse was blown you shouldn't have any DC voltage at VR plug when bike isn't running). 12v w/ bike off and 11.5 w/ bike running indicates the battery is doing all the work. Have you carefully inspected the connectors inside the VR plug (checked for continuity from terminal to red wire on other side of plug)? The problem has to be there or upstream, either the VR or stator. .
If your frayed red wire at the VR was shorted to the frame it definitely should have popped the fuse at the relay. I assume someone replaced it. My bike charges at 14 volts. .
Yes I recollect the fuse popping once. I had to replace it...I will check for continuity between red wire terminal at VR and wherever else it connects. Brand new VR. I'm understanding of the idea that it could be the stator but it makes no logical sense--stator passes both ohms test and is supplying ac voltage to regulator. If there is some way that the stator can still be at fault please enlighten me. I'm not that well versed when it comes to electronics.
Cam, the troubleshooting manual you provided is excellent. I need to test black multimeter lead to positive battery terminal and red multimeter lead to red wire connector. If I get over .2 volts there is a problem with the positive battery cable and/or relevant connections. Simple enough.
When I did that test I got a 9.3V drop. That is how I found the high-resistance fuse. Your system is made of 4 parts, stator, VR, Battery and wiring. Seems to me that you have proved the stator, VR and battery. Cam.
For the first red wire test in electrosport I am getting .1 volts. For the second test I am getting .7 which is way over .2. It says, bad connection in the negative lead from RR to battery (-). Check this connection all the way to the battery including the plate on which the RR is mounted. Best Solution: Connect the RR ground straight up to the battery(-) with an extra lead. How would I go about doing this?
Easy. Get some #10 auto wire about 3' long and 2ea 1/4" ring terminals. Crimp one on each end of the wire. Route the wire from the VR to the battery then connect one end to the neg battery terminal and the other to the VR bolt that has the ground wire attached. Then check your charging voltage. You can also route the wire from the VR to the ground stud on the engine like I did. Cam. PS while you are connecting the ground wire why not build a second wire and wire the RED VR wire direct to the battery +. Then you have the best of both. Cam.
For the yellow wire stator test it says any and all combinations of the 3 wires should give .21 but for this purpose it's .3 to .6. Does this include testing each individual wire connector then testing wire to wire? I find it very hard to get the meter leads in the wire connector when im testing an individual wire there isnt enough room without touching plastic. I'm afraid I'm not getting an accurate reading but what I do get is .2 ohms...I know this is outside of the proper range. For wire to wire test and combination of wire to wire I get .4. Anyways, the plate that the VR is bolted to is bulging in where the rivet attaches to it. This causes the back of the VR to not be flush with the frame plate. Could this be a problem related to no charge?
