Electrical issues...charging / not charging...

[rabbitnutz]

Hi, I'm Nick. I just got a bike. First bike for me. I'm kind of a car guy, but bikes are new. 1980 xs650. I've been lurking on the forums a bit, and now i need help with some advice. I was told it needed carbs cleaned (had that done) and it has a charging issue, so be advised for long trips...this is what i need help with.

So, i did some electrical tests with a volt meter to see what i was working with:

battery started at 11.49 volts. threw it on a charger, got to 12.49 while on charger.
left it on there for half an hour, when i removed charger, it was 11.56 and draining.

kick started it, revved it, and lights got brighter when revving (this indicates charging...right>?)
took it for a spin around the block, and about 3/4 the way around the block it stalled out, and i couldn't (kick) start it again.

immediately post ride: 9.62 and rising (?)
10 minutes later 9.45 and dropping

at this point i've turned the key to "run" and lights are still bright and normal looking...noticed battery acid level was at the low mark.

i cleaned all the terminals with a file and some dielectric grease, and checked the volts again. this time i got 10.51 and slowly rising (the rising thing weirds me out)

at this point i charged it overnight. When i came out the next day, i had 12.4v.
while idleing: 12.4
revved it a bit: 12.7
...ok. so i have some charging.

i tried the slap test by hanging a wrench, and when i turned the key on, it didn't slap against the cover. Took the cover off, and the nut holding on the rotor does seem magnetized when the key is on, just maybe not enough magnetization for a slap test?

after a ride around the block a few times, i had 12.82 and slowly dropping (tested when bike was off)

i filled the batter with distilled water, rode it around the block, and had 12.63 when i got back. because of my fear of a parasitic draw, i disconnected the battery overnight.
12.62 the next morning. Cool. Battery seems OK.

that night, i went for a longer ride. around 6 miles, with three small stops in between. at my third stop, i got the volt meter out and took a reading:
11.79 when idleing, and no change when revving.


Anyone have any ideas? should i just bite the bullet and get a PMA?

 

[NorazDad]

Get a new battery and then you can do the PMA swap. It took me months of frustration to realize it was the battery first and then I had some Reg/Rec issues that eventually got fixed with a jump...odd huh?
Get a new battery. You should be in the 13+ volts in the morning and after your ride.
Good luck.

 

[weekendrider]

Check your brushes.
The battery may be OK with the topping of water. Are the sides bulged or do the sides look straight?

 

[5twins]

Yes, check your brushes and replace them if worn too short. That's the usual first step when encountering charging problems on these because it's about the cheapest fix. It's also a common problem. The brushes are considered a wear item on these bikes. Next step is usually to test your rotor. Rotor output can change when hot, and it appears yours may be doing that. It charges cold but not when hot.

And when testing your voltage output, you need to rev it more than just a little bit. Rev it to 3K to 3.5K RPMs. Full charging output occurs by then. Revving just a little isn't going to tell you much.

 

[fredintoon]

Hi rabbitnutz and welcome,
from what you describe your charging system should work OK after you replace the dodgy battery.
And even if your charging system ain't working despite the headlight brightening test sez it is, don't go PMA except as a very last resort.
99% of the time it's less costly & more reliable to fix the stock charging system instead.

 

[rabbitnutz]

Get a new battery and then you can do the PMA swap. It took me months of frustration to realize it was the battery first and then I had some Reg/Rec issues that eventually got fixed with a jump...odd huh?
Get a new battery. You should be in the 13+ volts in the morning and after your ride.
Good luck.

not seeing thirteen, but close. i'm starting to wonder if i have a parasitic draw / short

Check your brushes.
The battery may be OK with the topping of water. Are the sides bulged or do the sides look straight?

sides are not bulged, battery is 100% normal looking.

Yes, check your brushes and replace them if worn too short. That's the usual first step when encountering charging problems on these because it's about the cheapest fix. It's also a common problem. The brushes are considered a wear item on these bikes. Next step is usually to test your rotor. Rotor output can change when hot, and it appears yours may be doing that. It charges cold but not when hot.

And when testing your voltage output, you need to rev it more than just a little bit. Rev it to 3K to 3.5K RPMs. Full charging output occurs by then. Revving just a little isn't going to tell you much.

i checked the rotor the other day ( more on that in a minute) while i was doing that, took a look at the brushes. they were short, and getting within a about a 1/16th of an inch to the wear line.. worn...but should still work. the revving thing is tough to gauge accurately because my tach is broken, but i'm basically pinning it for a few seconds. if i'm not pinning it, i'm giving it enough where i would expect it to at least do something.

Hi rabbitnutz and welcome,
from what you describe your charging system should work OK after you replace the dodgy battery.
And even if your charging system ain't working despite the headlight brightening test sez it is, don't go PMA except as a very last resort.
99% of the time it's less costly & more reliable to fix the stock charging system instead.

please speak to me regarding the reliability thing. i've heard some people say the simplicity and reliability of a PMA & Ignition replacement (pamco, or i'm honestly leaning towards a HHB complete CDI set up.) is the way to go if i don't want to ever question it again, but i've yet to hear the contrary opinion. I'm not gonna say money is no object, but i'd gladly pay to never worry about electrical again.


now, to update everyone that's curious on my progress. First, i'd like to say i'm sorry for explaining it out in this weird timeline format, but at least i'm writing things down. I'll try to summarize a bit better so i'm not so long in the tooth.

Saturday( 5 days ago) i took the side cover off, and went to inspect and test the rotor and the brushes...trying to aim down on what i need to replace.
- checked battery before doing anything: 12.3 volts.
-brushes are indeed worn. not quite at the wear line, but about a 1/16th to 3/32nds away from the line. worn, but in theory should work.
-the rotor was a but scoured. probably as to be expected for factory equipment that's from 1980. I removed the stator to get to the rotor, and tested with an ohm meter ....now, i honestly have no idea if i was using the right setting on my multi meter ( just used regular ohm..not killa or milla ohms.) and i got 1.3 to 1.7 ohms. (it was jumping a bit, as i was moving around...but was mostly settling on 1.3)

i cleaned up the rotor surface with an abrasive sponge, reassembled, and it ran fine afterwards, with still the same voltage. i was tired and hot and aggravated, so i didn't bother riding it around the block.

THE NEXT NIGHT (sunday night):

After work, i came down and tried to take it for a ride. hot and humid as it could be. 10-15 kicks, started once for a few seconds, then died out (possibly my bad with choke) after that, it wouldn't start. said fuck it and gave up. it was hot.

TONIGHT:
-check old battery: 11.97 volts. (again, sat for four days, and i tried starting it a bunch to no avail before it sat)
-installed new battery. New battery had 12.72 volts. ( i had put electrolite in , and charged it sunday through tuesday, let it sit tuesday night till thursday (tonight))
-rode across town to school( 15- 20 minute ride): 12.92 when i got to school (yay?)
-was at school for about two hours, battery when i went to leave was 12.82
- rode back home, when i got home batter was 12.86


this is annoying. thank you all for your help and understanding.

 

[peanut]

. i'm starting to wonder if i have a parasitic draw / short



.

could well be a parasitic draw.
Are you using the steering lock ? you may not be aware, as I wasn't , that if you turn the ignition key to the far right it switches on the rear parking light . Make sure that you turn the switch back one click if using the steering lock.

I still have something flatting my battery overnight and I haven't had the time or inclination to investigate.
if you look at your fuse block there is a large dia red wire feeding the fuse block from the positive battery terminal. It has a bullet connector mid point for quick battery isolation.
If you disconnect that red wire connector you isolate the battery from the bike so that will solve the overnight battery draw temporarily at least.

You need to use the lowest setting on your multimeter ,(which usually also has a continuity test ). If you put the leads together you should hear a whistle from the multimeter .

Any reading less than 3.5 ohms from the copper rings to the rotor body means you need a replacement rotor. Ideally you should be seeing around 4- 5.5 ohms
If you have the stator off clean up the rotor's copper rings and put some new brushes in. The stock charging system works really well .
This video is pretty basic but might give you a better idea of how the charging system works. On your model year the rotor is grounded by the combined regulator /rectifier . Clean the terminals in the stator wiring connector also ,it might improve things.

 

[rabbitnutz]

could well be a parasitic draw.
Are you using the steering lock ? you may not be aware, as I wasn't , that if you turn the ignition key to the far right it switches on the rear parking light . Make sure that you turn the switch back one click if using the steering lock.

I still have something flatting my battery overnight and I haven't had the time or inclination to investigate.
if you look at your fuse block there is a large dia red wire feeding the fuse block from the positive battery terminal. It has a bullet connector mid point for quick battery isolation.
If you disconnect that red wire connector you isolate the battery from the bike so that will solve the overnight battery draw temporarily at least.

You need to use the lowest setting on your multimeter ,(which usually also has a continuity test ). If you put the leads together you should hear a whistle from the multimeter .

Any reading less than 3.5 ohms from the copper rings to the rotor body means you need a replacement rotor. Ideally you should be seeing around 4- 5.5 ohms
If you have the stator off clean up the rotor's copper rings and put some new brushes in. The stock charging system works really well .
This video is pretty basic but might give you a better idea of how the charging system works. On your model year the rotor is grounded by the combined regulator /rectifier . Clean the terminals in the stator wiring connector also ,it might improve things.

I"m not using the steering lock / park feature which keeps the rear light on. coincidentally, i've pretty much only been riding at night, so i would notice the light on when i go to walk away.

thanks for the heads up about the red wire. I've been thinking about getting a terminal disconnect switch in the mean time until i figure this issue out.

as far as i know I measured the rotor right, but i think I'm going to take everything apart again and check it again, as well as all of my connections. I'll post up pictures of what i'm doing so you guys can more directly tell me if i'm doing it wrong. haha

 

[Paul Sutton]

Loads of suggestions for you to try - I agree with the others in making sure the battery is 100% first.

When I had trouble with my battery not charging I followed "Curly's Charging Guide" to the letter. Just Google it even though it is copied and referenced on this website in several places. I do not know Curly but the guide is a master piece and easy to follow. At the end of the article Curly says something to the effect that most problems are due to worn brushes and dirty connections. Check all connectors even if a new battery solves your current problems. Also, brushes can cause problems before they reach the minimum specification lenght.

Regarding poor connections, my problems were due to a 0.7V drop across the connector from the battery to the red wire, 0.3V drop over the red wire main fuse and a further 0.3V drop on the connector between the red wire and the ignition switch. So I cleaned all the electrical connections using the vinegar/salt method (See Youtube) and made sure they all clamped tightly - My problems immediately went away. The total 1.3V drop to the brushes had made the alternator output low even though the slap test appeared good.

Best of Luck