Stator output voltage? Electrical trouble on WR426

This bike has been like a Ford Ranger I used to own. The engine runs like a champ but the electrical systems have been crap.


PO had installed Baja Designs kit and Trailtech Vapor. The lights/directionals were always a bit flaky but seeing as I don't drive on the road very often, no worries.


At some point nothing was working. It didn't take long to find the BD reg/rec was good at idle, 12.4V, but putting out over 19V when revved up. BD is close by me so I just went over there and picked up a new one. Installed it and..... nuttin'. I checked the reg/rec output voltage and it was 12.6V at idle and 6V when revved up. WTF? I removed the battery conneciton and checked again and sure enough, 6V. So before I go back to BD to see about a new reg/rec, I was curious if anyone knew the correct AC output of the stator. I checked mine and at idle its ~12V AC, at 4k rpm its ~ 24V AC, and at 5k rpm is ~ 36V AC. Anyone know if this is reasonable?


Would 19V kill anything associated with the BD kit? Bulbs, flasher, etc.


much thanks Scott

You cant test the output of the r/r without a battery attached to it, the voltage will always be low

Arent there adjustment screws on the side of the reg/rec that you can turn to set your outputs?

I seem to recall mine had some on it.

Arent there adjustment screws on the side of the reg/rec that you can turn to set your outputs?

I seem to recall mine had some on it.

Yes, but to set the voltage you need it attached to a battery or capacitor

Similar charging issues here, on a WR2006 450Fv ....I have exhausted the local dealers with questions on LOW RPM charging...nobody has confirmed exactly what the system should put to the battery at idle and low RPM, and the shop manual is no help either simply states that @ 5000RPM Reg/Rec to the battery will be 14V. All is well and good on my bike at the high RPM...I see 14V spot on..BUT at idle, the battery is only receiving 9V, which amounts to DISCHARGE, and in a short time, a dead battery. So in the vast collective knowledge in ThumperLand, can anyone give me a LOW RPM charge number?? In the mean time I am heading out to install the freshly charged battery and taking my multimeter along to look for resistance values and V's etc along the charging system ...would be nice to know what I should be seeing at idle revs.



You will destroy the battery. I went through 2 shorai's and the stock battery before I figured it out. The battery will swell up and then put a drag on the charging system to the point the bike won't run. I got stranded on the side of a mountain in Silverton CO.


The Baja rectifiers will go bad. keep an eye on that charging voltage. It should go up a little when you rev it but stay around 13.8v.

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