Yamaha XS650 Not charging. Testing the rotor How the charging system works

[@RamblinVan]

One year later, my charging problems are bad enough that I did a bit of googling and here I am again. Thanks once again! Time to invest in a PMA system I guess.

[@brianobrien]

Is there a replacement rotor that is a permanent magnet for the XS650 apart from the kit assembly.

[@cb400fhonda6]

Brilliant

[@paulderrick6095]

Thanks a lot. I especially liked the 9volt battery trick.

[@blimeyolriley]

no you can test the rotor by removing the brush assembly on the stator and putting your multimeter prods through the brush holes but its a real pita to do without shorting the prods somewhere. Better to remove your cover and stator completely then you can also clean the copper lands on the rotor and check your stator wiring hasn't got a short or break somewhere out of sight.

[@EvLoutonian]

Great vid, thanks!

[@blimeyolriley]

+EvLoutonian thanks for the feedback much appreciated ,glad it was some help

[@RamblinVan]

Youre the best, thanks

[@hootinouts]

Thank you for sharing your knowledge. I am having charging problems with my 1981 XJ650 Maxim and still haven't solved the problem. The stator phases all check out at .5 ohms, brushes are new, regulator rectifier is new. Beginning to suspect the rotoe is the culprit. can they test good at rest and fail when spinning, perhaps from a break in a winding that opens up under the influence of centrifugal force?

[@blimeyolriley]

+E.PLUMBUS UNUM you haven't said what problems you are experiencing ? I would suggest that you disconnect the regulator/rectifier connector and then use a multimeter to check voltages at the stator connetor terminals.Check that you have 12v+ at the outer copper track on the rotor with the ignition switched on. if you have then check that the stator ground is being grounded by connecting the inner copper track on the rotor to the bike frame .If you still haven't got a AC charging voltage on the 3 white wires at the stator wiring connector then there is something wrong with your brush holder assembly or the wiring from the stator to the regulator connector like a short . make sure your stator wires are not crushed anywhere when the stator is bolted back on.

[@johncooper7242]

Apologies for the late reply. I know that you will have solved your problem by now but for the benefit of others that arrive here I'll answer your question. I am not familiar with your bike but I would guess that as your model is a late one then your rotor is a PMA type which means it doesn't need to spin in order to create a magnetic field ( like the pre 1980 models,) when supplied with 12v+ and a good ground. 1. Provided that you can test and confirm 12v+ at the outer brush and rotor ring with the ignition switch on ... 2. You can verify that the inner rotor ring and associated stator brush is earthed or grounded to the battery negative via the chassis. Then your Rotor should create a magnetic field and be working correctly as it should. if the rotor test ok then suspect either the wiring from the Stator to the rectifier/regulator being shorted, pinched or cut etc or a short at the Stator brush assembly or a faulty Regulator or Rectifier.

[@angelasangel6275]

@@johncooper7242 wrong

[@Exo5432]

Good job!

[@alexb4876]

Hi bro! When i put stared my bike, the regulator rectifier its so hot and the battery not charge... What do you think about this? Can you help me? Thanks!

[@juliannws1]

hi is it necessary to remove the rotor to test it?

[@DannyC2345]

Juliann Salinas I’d like to know that too ??

[@johncooper7242]

no you can test it with the rotor on the bike. all you need to do is disconnect the stator electrical connector at the regulator and isolate the alternator. Then test the rotor with your multimeter