6 replies to this topic
  • jmkybf

Posted February 23, 2009 - 05:13 PM


Ok, I have been reading up on regulators/rectifiers, and here's my situation. My voltage regulator went out on my 98 wr 400. I have decided to replace it with a regulator/rectifier because I am in the process of making the bike street legal, and I need DC for the turn signals. I have a regulator/rectifier off of a wr250 that I am trying to wire up. I have both the wiring diagrams from both bikes. The regulator/rectifier has 4 wires-yellow, white, red, and black. The white and yellow go to the stator on the wr250, and the red and black are the DC + and -. As all you guys probably know the wr400 stator is chassis grounded. I ran the yellow wire to the wr400 stator, the white to a chassis ground, and the red and black are my DC ground. I have the regulator/rectifier insulated from the chassis in the air box, and my DC ground is not grounded to the frame, it is grounded to the regulator. I am not getting any voltage out of the DC wires. The bike starts and runs fine though. I connected the regulator/rectifier to the stator via and chassis ground via the stock tail light connectors. The stock voltage regulator is taken off of the bike, so that terminal is empty. I don't think that that should affect the regulator/rectifier though. Anyone have any ideas?

  • Birdy426

Posted February 23, 2009 - 06:03 PM


You have to float the ground onthe WR400 lighting coil. Baja Designs has instructions on their web site.

  • jmkybf

Posted February 23, 2009 - 07:31 PM


I wired it up using their instructions here
I was under the impression that I did not have to float the ground as long as I have the rectifier insulated from the chassis

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  • Birdy426

Posted February 23, 2009 - 09:43 PM


I ran the yellow wire to the wr400 stator, the white to a chassis ground,

You don't have the regulator isolated...

  • jmkybf

Posted February 24, 2009 - 06:03 AM


Please correct me if I'm wrong, but isn't that what Baja Desgin's wiring diagram tells me to do? I thought insulating the rectifier causes the DC circuit not to be grounded out on the chassis.

  • Birdy426

Posted February 24, 2009 - 11:09 PM


Disclaimer: I'm not a sparky-head electrical engineer, but this is how the whole regulator/rectumfinder deal was 'splained to me: First, the WR250 voltage regulator doesn't make much creates DC for charging the e-start battery only, not for powering the lights and such. With that said to set your expectations, if you don't hav a battery or capacitor across the wires, or a load on them, you won't get any DC out of the regulator/rectifier. The regulator responds to changes in potential...that is, a demand on the system. It charges your battery when the battery voltage drops below the voltage level output by the stator. If the circuit is not complete with a battery or capacitor, the regulator will not detect a change in potential, and therfore will not "port" any current out. If you want to run without a battery, you will need to use the first method in the B-D instructions, which require that you float the ground.

  • jmkybf

Posted February 25, 2009 - 06:03 AM


Ok, that makes sense now. Thanks for your help.


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