yx600 not charging

Hi all

I have recently bought a yx600 radian, which to date has run perfectly, super bike. The headlight was a bit dull so I replaced the bulb with a rally use bulb 100watt. Since then the battery has not been charging. I changed the bulb back and it still only shows about 10.5volts. I have followed all advice in the Haynes manual, ohms at the 3 ends of the alternator cable are all showing correct according to the specs. On dismantling the alternator I have found it’s the brushless type so cant even check the brushes. All appears clean inside the alternator. Is there anything else I am missing? Even when I rev the bike the voltage dooesn’t change, it just sits a about 10volts across the battery terminals.

Help,
love the bike but won’t set off anywhere as fear of it dying within 5 miles.

 

It sounds like either the alternator or regulator is bad or the battery has a shorted cell. If the battery charges up fully with a battery charger and holds a a full charge then you should look into replacing the regulator. The only real way to test it is to replace it with a good unit and check to see if it cured the problem but make sure the connector between the regulator and the alternator isn't corroded or burned.

 

According to the parts fiche your alternator should have brushes. Perhaps this is the problem.

 

Take a small feeler guage say .002" and hold it about a half inch from the alternator cover and turn the key on. With a good battery, the rotor inside should become an electro magnet and you will see the feeler guage touch the cover. If it does, this means the rotor, brushes, and the regulator are probably working and it's either the stator or the rectifier are causing the problem. Yamaha used to teach this 25 years ago.