Headlight not working on 08 WR450

6 replies to this topic
  • lewis87

Posted June 01, 2013 - 09:29 AM


The headlight on my WR450 is not working. I tried a new bulb but it still doesn't work. I'm not good with electrics so I don't know where to start with this, what are the likely causes? All the wiring and connectors look fine.

  • SurfaceToAir

Posted June 01, 2013 - 10:19 AM


I would start debugging by putting a muli meter on the two pins going to the light, when the bike is running. If you get powere 12-14 volts, then it's something in the light...
Also, does the tail light work? I think though they are on different circuits, where the tail light is on when the bike is 'on' , regardless if the motor is running...
There are only two fuses in the circuit- one on (-) wire and one on (+). But they are essentially in same circuit.
I suppose that the stator is the next thing to check, but if the bike is running, I think it's working, though someone else here will know better how to test it. I would think the bulb would still light, though dimly, if the stator was not pushing enough volts..?

Prob not much help there, but maybe something's to think about?

I burned my light out a couple weeks ago an need to get a new bulb. Hopefully I am not entierly in the same boat as you.

Good luck,

  • lewis87

Posted June 01, 2013 - 10:47 AM


Thanks for the help,

I tried putting a multi meter set to AC on the pins of the headlight plug when the bike was running, I didn't get any reading at all on my old analogue multi meter I got from my dad. The tail light is working as normal when I turn the ignition on. I've read some things about the regulator rectifier, I wonder if it needs replaced? I don't know how to test it.

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  • SurfaceToAir

Posted June 01, 2013 - 12:16 PM


Ok- the current at the light, starter switch, and I think everywhere after the rectifier is dc. There is one hot and one ground going to the light. Maybe check it again. Also can check the specific circuit, at least ground, by using a test light or equivalent by connecting ground to neg battery post and other to neg wire. Try same for positive, though I am not positive that will work due to stator

  • Krannie McKranface

Posted June 01, 2013 - 12:31 PM


Pull off the headlight, tank, seat and left side cover, and start looking for an un-plugged harness connection.

  • lewis87

Posted June 02, 2013 - 08:31 AM


All the harness connections under the tank, seat, side cover and behind the headlight looked ok. I checked the resistance of the lighting coil like it says to do in the manual and that was within range. I also checked the voltage of the battery when the bike was running and this was 13.9v at idle and rising a little when I would rev the bike. I checked the voltage of the plug going into the light and this was showing just 0.34v.

So would I be right in saying my stator seems to be working fine, so could it be the regulator rectifier at fault?

Edited by lewis87, June 02, 2013 - 09:26 AM.

  • lewis87

Posted June 03, 2013 - 10:28 AM


I took the stator cover off and the stator had rubbed through and broken the wires for the headlight. I guess I didn't install it correctly last time I had it off :naughty: I repaired the wires and the headlight is now working :thumbsup:


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