HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
fasteddie45

2003 wr450f headlight problems

6 posts in this topic

I have a 03 wr450f and my headlight is super dim when idling (can't even see past front fender) and as soon as i start going the light seems fine for a couple of seconds then the bulb blows i changed the rectifier/ regulator same thing is still happening can someone help me out please

Share this post


Link to post
Share on other sites

You will need to measure your voltage at the headlight terminal. was it a new or used reg? could be the stator I suppose, are you sure you had the right bulb? the light circut is AC not DC. Not sure if that would make a difference or not....

Share this post


Link to post
Share on other sites

I don't have a service book for the bike and every where i look wont give me an answer for the voltage on the headlight terminal. the rectifier is brand new yamaha oem. And i don't think it's the stator because my battery is holding a charge perfectly fine. And yes i have the right bulb.

Share this post


Link to post
Share on other sites

WR450s have two essentially separate electrical circuits. There are two poles off the stator. One of them goes to the regulator/rectifier, producing DC to the battery, starter, and CDI. The other goes to the lighting, and the regulator only side of the r/r. The regulator side is in parallel with the lighting. I'm guessing a bad ground on the r/r could lead to excessive voltage on the AC side. 

 

I managed to find a manual in perfect shape for $11 shipped off ebay. It's for an 04 rather than an 03 but there aren't many differences. I don't see any that cheap right now but keep your eyes open and pick one up when you see one. http://lolinter.net/wr450/wr450diagram.pdfis the wiring diagram, http://lolinter.net/wr450/WR450.pdf is a manual but it's trilingual and in my opinion not as good as the paper one. Good luck. 

Edited by toten

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0