Yamaha wr450 regulator/rectifier testing

6 replies to this topic
  • yamahahahahaha

Posted February 25, 2007 - 09:55 PM


Can anyone tell me how to connect a multimeter in order to test the Voltage regulator/rectifier on my WR450?

Problem I have is that the bulbs constantly blow when I increase the idle.


  • CRF45OX

Posted February 27, 2007 - 02:43 AM


shes ****ed, i had the same problem, i bought a new one from oem thumpertalk (heaps cheaper than locally) and havent had a problem since.

if you want to check - where your light plugs in - put the 2 meter leads across the 2 terminals and set it to ac volts (when u rev it, it will probably say about 28V and it should only be 12 - 14V. Remember.... AC not DC!

good luck mate

  • yamahahahahaha

Posted February 27, 2007 - 05:59 PM


Thanks for the reply. Shes definitely gooone. MM reading of 27v.

Thanks for the help.

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Posted February 28, 2007 - 12:53 PM


I replaced mine with a Baja designs. I think my stock reg. is in a box in the garage. PM me and I'll look for it, if you want it!

  • ausgeflippt13

Posted February 28, 2007 - 02:52 PM


It's not ever the rectifier's fault (well, never say never...); it's almost always the fault of a bad ground. Regulator/rectifiers need a FANTASTIC ground in order to function well, and without it the current will pass thru the system unperturbed by the reg/rec.

I had my reg ground to the same place as my lights (underneath the seat on the frame) and after blowing a bulb upon testing, I realized the ground wasn't going to do. So, I moved it to a motor mount (for JUST the reg, nothing else should go there) and everything has worked peachy since. I had a choice of two reg's: the Yami brand one at $60 or the generic one used for Harleys (tells you something about harleys :applause: ) for a mere $12 or so.

It's all about grounding! :applause:

  • yamahahahahaha

Posted March 08, 2007 - 03:23 PM


Replaced the reg the other day and shes running sweet. I hear that the wr450regs can be a bit dodgy so I ll keep an eye on it.

Thanks for all help

  • AMG_Eric

Posted March 10, 2007 - 10:56 PM


baja designs replaced mine with a ktm one. no problems since. the yamaha ones are know to SUCK.


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