Tip of the Week #4
Here is an easy way to test the Voltage regulator on a 2005-2009 if you suspect it is bad. For this test the wire to the battery will be called B+, the two pins out of the stator plug will be called Pin 1 & Pin 2, case will be ground.
1. Disconnect the ground cable from the battery.
2. remove the B+ wire from the circuit breaker.
3. Attach an ohm meter between B+ and ground (by the way the case is clear anodized therefore when measuring ground you need to measure it at the bolts). The resistance should be over 2meg Ohms, or an open circuit depending on your meter.
4. Measure resistance between B+ and Pin 1 or B+ and Pin 2. There should be great than 1megohm, or an open circuit depending on your meter.
5. Measure resistance between Pin 1 and Pin 2. There should be more than 1megohm.
6. Measure resistance between Pin 1 and ground and then Pin 2 and ground. should be greater than 1megohm.
If any of these values are less than specified you have a bad voltage regulator. This is a good test to confirm that it is bad however there has been one time that I did this test, everything measured fine but the VR was still bad. So what this means is if you are less than specified resistance you definitely have a bad VR. If you are not less you may still have a bad VR but should double check the rest of the system before you spend money for a new VR.
Tip #4 cont.
Testing the Stator.
Let me preface this be saying you need to be extremely careful when performing the AC voltage check. It should not kill you but it is sure to scare the shit out of you of you let the probes touch each other or ground and will probably damage your meter and probes. Perform this test before the beer.
To test the stator start with a resistance test.
1. Remove the VR plug from the stator.
2. Measure the resistance across both pins of the stator plug. The resistance should be 0.5ohms or less, usually it is zero on most meters. Do not forget to subtract the resistance of your meter leads. If it is an open circuit the stator windings are damaged and the stator needs to be replaced.
3. Measure resistance from Pin 1 (either Pin) to ground and then from Pin 2 to ground. It should be an open circuit in both cases. If it is not then that means the windings are shorted to ground and the stator is bad, the plug may be damage or the rotor has interfered with the wires. Remove outer primary and rotor to inspect stator.
4. If stator passes resistance check you can check the output voltage. Again BE CAREFUL!!:angry: remove the vR/Stator plug. Start the bike, measure AC voltage across the to stator pins. At idle you will have around 15-20VAC, the voltage will increase as the RPM is increased. The voltage can go up to about 60VAC or more at high RPM. Have a buddy help you run the throttle, keep you eyes on the probes and do not let them touch each other or ground. If you see voltage as indicated below the stator is functioning.
Don't forget to plug your VR back into the stator plug when your testing is done. I can admit it, I made that jr mistake and was left stranded on a prototype fuel injected bike
