[Colokid]

Hello everyone. New here and new owner of a crf450x. I was hoping for some help from the crf community.
Have had the bike maybe a month now. Bike runs great. Haven't done a serious ride with it yet, and no long durations yet. Battery has been dead since day one, so just either kick started it or more recently removed it and rode without a battery.
My Issue is electrical - Headlight and voltage specifically. Headlight doesn't work, only getting 1-3 volts at bulb. Taillight very dim at idle, but gets brighter with revs. Recently I reinstalled battery and checked voltage at battery too. 18-20 volts while revving motor! Taillight is on though with good, constant brightness. Still no headlight.
Honestly, I think it is a regulator/rectifier issue, but the manual procedure to check it didn't yield much info for me. Maybe I missed something.
What is the best way to troubleshoot my issue? Is there a previous post or how-to on here somewhere?
Thank you in advance.

[Colokid]

A quick update this morning...
I did the test at the 4-wire connector for the rectifier again, at the alternator side of the connector.
Got the voltage for the battery at the red and white wire. For the others I got 2, 2.7& 2.3 ohms (yell,green,wht respectively).
This means the alternator wiring is ok, right? Is it likely a bad rectifier/regulator?
Thanks.

[JimDirt]

Welcome to the site !!\:D/

From the sounds of it , that is what i would go with , i would also assume that the headlight bulb might have blown out , you can hook it straight to a charger or battery (the bulb) to test it (single bottom lug =Ground , either top would be light power (high/low), there is a possibility that the lighting coil on the stator went bad as well , but the regulator might possibly also have put too much juice to it and fried it , try not to run to too much while its putting out so much voltage to avoid frying anything else , 15.5 should be the max voltage at the battery (charging voltage) at 5,000 rpm (don't hold it at that RPM for more than a few seconds) , normal at idle should be 12.5-13.5 volts

[Colokid]

Hey thanks for the reply JimDirt.
I forgot to mention that I pulled the bulb too and jumped it to my truck battery and it worked fine. I will fetch a new reg/rectifier and see what the charging system does then.
I will take your advice and keep it in the garage until I have things sorted out.
Thanks again.

[Colokid]

Well, installed new regulator/rectifier yesterday and it did not fix the low voltage to the headlight issue. Checked voltage at various locations and still only about 2 volts going to headlight. At the battery it shows 15 volts at high idle, so I think I'm good here now. It isn't spiking too high anymore.
I ran direct wires from battery to headlight while at idle and the bulb lit fine. So, is it time to look at the alternator again?

[Colokid]

Well, installed new regulator/rectifier yesterday and it did not fix the low voltage to the headlight issue. Checked voltage at various locations and still only about 2 volts going to headlight. At the battery it shows 15 volts at high idle, so I think I'm good here now. It isn't spiking too high anymore.
I ran direct wires from battery to headlight while at idle and the bulb lit fine. So, is it time to look at the alternator again?

[JimDirt]

Yea , looks like its heading in that direction , and you can't replace just the headlight part of the stator , so if the lighting part of the stator is bad you have to replace the entire unit

On the diagram , the headlight wires go from the stator to the Regulator and to the light , its the Yellow wire out of the Stator and into the Regulator which turns to Blue going to the light

So before swapping out the stator , work your way from the stator to the regulator on the Yellow wire , and try to locate where the Blue wire joins the Yellow , then trace that to the headlight testing voltage along the way , the bike must be running , unless you do most of the testing using continuity , then once everything is located , switch to Voltage and test output while running for short periods of time , just to eliminate a damaged wire or connection