13+ amp current draw with switch 'on'

[xs650newb]

Hey guys,

I have a 1977 XS650.

Bike died on me and I had to have my wife come and give me a jump start.

Get it home and battery is shot. I just replaced the battery with a new, sealed AGM battery.

When I start the bike the voltage on the batter was less than 12 volts and when you rev it up it increases slightly.

It turns out that with the key 'on' (and the bike not running) the battery is pushing 13+ amps. I turned the switch off to diagnose.

When I unplug the plug with the three white wires coming from the stator (and the yellow wire for the safety relay) the current load in the 'on' position drops down to a reasonable 3 amps.

I removed my alternator brushes and measured the slip ring resistance and it is about 1ohm. So I guess my rotor is bad.

Anyways, I checked the bike a few weeks ago and it was charging perfectly and the slip ring resistance was perfectly in spec.

Any idea what can cause a rotor to fail so quickly? I obviously need to fix the underlying problem before I purchase another rotor.

Best,
adam

 

[jd750ace]

If your bike is a 77 then a 37 year old winding lying down can happen at just about any time. If you have just brought it back around to running condition then the heat and vibration of coming back to life could have easily finished off a weak spot.

 

[xs650newb]

Fair enough.


Ah, man. Now I have a real problem.


Do I get a rewind or go with hhb pma?

Adam

 

[DIRTY DOG]

if everything is good exp for the rotor replace the rotor with a new or rewound if the stator and the rotor is bad it cheeper to replace with a pma set up

 

[jd750ace]

I agree with Dirty Dog. There's enough spares out there to get you rolling for relatively easy money on a 1 part swap. The PMA is a good product, no doubt, but you don't "Have To" right now, unless you just feel like you should.