2008 YFZ 450 headlight issue

zilla68

zilla68

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My buddy put this bike up dirt cheap so I had to buy it. 

A kid at work bought it brand new in 2010. he rode it like 4-5 times, then moved away. It was kept in their shop for a couple years, and he had it shipped to somewhere like maryland or dc. While it was at his parents it was stolen, and recovered next day with different plastics on it at a off road area monitored by rangers I believe it was. They stopped them to check for registration and the guy bailed off and ran lol. He got the bike back, moved back here and had it shipped back here. My buddy ended up buying it and kept it as a spare, ridden 2 times in last couple years.

I get it, plastic looks like chit, so I replaced it, and it had 2 blown headlights. So I buy new LED lights off ebay. install and bam blow within 10 seconds. From what I could tell the voltage regulators on these are known to cause issues. I checked it and it seemed bad, buy a new one, install, install new bulbs and bam blow again. 

can the stator cause the lights to blow? I thought it was only the voltage regulator if it was out.

any ideas or help?

I did find a wire in the harness unplugged, it was a black and I think black yellow so I tried it plugged and unplugged, really no change.

I did check the grounds on the headlights and it shows grounded properly to multiple points on the bike.

 
The lighting circuit on your bike is AC and your LEDs require DC voltage to operate correctly. Your LEDs may be burned out or flickering dimly due to the AC input. If you install a regular incandescent bulb do they burn out?

 
Whats the voltage at the battery with the bike running? 

 
Sandkist said:
The lighting circuit on your bike is AC and your LEDs require DC voltage to operate correctly. Your LEDs may be burned out or flickering dimly due to the AC input. If you install a regular incandescent bulb do they burn out?
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the bulbs in it were regular bulbs and were blown, so I just changed to led since they were blown. I guess I'll get some regular bulbs and see what happens.

 
wopachop said:
Whats the voltage at the battery with the bike running? 
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if I remember it was about 13 volts or so. battery wasn't draining while it was running, so it seemed to be charging. new battery also.

 
zilla68 said:
if I remember it was about 13 volts or so. battery wasn't draining while it was running, so it seemed to be charging. new battery also.
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I would do the test again but this time rev the bike and make sure you see 14v.

Does the brake light work? Neutral switch light? All the lightbulbs on the bike are 12v DC. Able to handle 14-15v DC no problem and not blow up.

My best internet guess is the thieves damaged a wire or connector related to the headlights when they switched out the plastics. 

 
wopachop said:
I would do the test again but this time rev the bike and make sure you see 14v.

Does the brake light work? Neutral switch light? All the lightbulbs on the bike are 12v DC. Able to handle 14-15v DC no problem and not blow up.

My best internet guess is the thieves damaged a wire or connector related to the headlights when they switched out the plastics. 
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all lights work but headlights. neutral switch works, I did replace the switch on the motor because the neutral switch wasn't working, installed a new one and it started working just fine. tail light works also. I'll rev it and see what it registers.

 
wopachop said:
I would do the test again but this time rev the bike and make sure you see 14v.

Does the brake light work? Neutral switch light? All the lightbulbs on the bike are 12v DC. Able to handle 14-15v DC no problem and not blow up.

My best internet guess is the thieves damaged a wire or connector related to the headlights when they switched out the plastics. 
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did the test tonite, while revving  it goes to 14.4 volts.

 
does your head light have power with the key on and the engine off. if not ac voltage is going to the headlights and will kill led lights 

 
Your headlights have no connection to your battery or the battery charging circuit. If you want to verify voltage for your lights you should check it at the connector for the bulb. Make sure your meter is set to alternating current and your engine is running.  Since you have already replaced your regulator the solution to your problem could be as simple as installing new incandescent bulbs.

 
Are you guys sure?? Sorry for the bad info zilla. Could have sworn the headlight ran off the battery. I do the maintenance on an 04yzf. Would have bet money we killed the battery more than once leaving the headlight on. Not home to check or i would just turn the key and check. Glad the other members were here with the correct info. 

 
Now you have me second guessing LOL. Pretty sure headlights don’t work without the engine running. Gonna go check right now.

 
Ok so double checked on a 2006 YFZ. Tail light runs off of battery ( turns on with engine off, key on, headlight switch on). Headlights do not turn on when engine is off so no battery connection. Headlights are strictly powered by the stator.

 
anyone had their front plastics off lately? I had a ground unhooked I think it was black and maybe yellow black, male and female. I've tried them hooked and unhooked.

 
Sandkist said:
Your headlights have no connection to your battery or the battery charging circuit. If you want to verify voltage for your lights you should check it at the connector for the bulb. Make sure your meter is set to alternating current and your engine is running.  Since you have already replaced your regulator the solution to your problem could be as simple as installing new incandescent bulbs.
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i'll order some bulbs tonite and see what happens. I checked the connectors before and if i remember right i had 12v at them, its been a couple weeks, i'll try it again.

 
ok so the 2009 450r is the first year with fuel injection and it runs the headlights off the battery. the 2008 450 run the headlight off the stator i have a 2007 450 that i installed the trail tech stator in so i could run hid. the kit also rewires the headlight switch to have 12v dc from the battery. they come stock running 14v ac to the head light i hope this clarifies some of the confusion.  

 
got the regular headlights in and installed. fired it up and so far they haven't blown.

Now I don't understand why the led were blowing, they've sold 1000's it shows. i guess time will tell if they last, but they lasted 1 minute longer than the leds now lol.

 
The other guys were correct in the initial responses. Your bike uses 12AC headlights. LED are designed to run off DC battery power. 

Sounds like in 2009 the bike switched to EFI and also switched over to 12v DC headlights. The LEDs should work there. Which is why they sold so many. The description should be written better to say it will not work with certain models. If it said something like 2009 and up, you would have never bought them. 

 
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