charging issues

ahhhh i need help just bought a 85xj700 battery was dead so i got a new one installed ran fin for a few days then it died i charged it up ran fine for a few days then dead again so i got it started and checked to see if it is charging while running its not i have no idea where to start looking for the problem any advice will be greatly appreciated

 

Do you have a multimeter?

You need to check the battery with the bike running.Connect the meter (on DC voltage check) and get the RPM's up above 2K-2.5K
You should be showing around 14.5 v +/-
If you're not close, definitely a charging issue, Could be your alternator brushes or your Reg/Rect unit if it's low

 

checked that today im only getting about 12v

 

-check wiring to/from battery; unplug big connector from regulator/rectifier and check the connectors themselves for signs of overheating or corrosion;

-check alternator brushes. They're mounted in the alternator cover and are easily accessible.

 

wooo hooo im running found two wires coming from the alternator both broken rewired them and now its working fine thanks for the help

 

scratch that died again

 

You still need to verify that your battery is seeing +14 volts at 2000rpm. If not, you should check out your alternator brushes. If they are still good, you might need a new regulator. And given that you had some broken wires odds are pretty good you may have a damaged regulator.

 

Robert, I have checked my brushes on my 82 seca 750 and they have plenty of life left in them. I cleaned the rotor as well and I am only getting arround 13.75 volts at 2000 to 2500 rpm. Is there a way to check the rectifier/regulator? Any feedback would be great. Thanks in advance

 

ok i checked the brushes one is alot shorter than the other about 2mm

 

Woodzie, 13.75 may be just fine, it depends upon the meter you are using and the contact you are making. Are you using an analog meter (with a needle) or a digital? Do you see any oscillations on the voltage reading (ripple)? Have you gone through and cleaned all of your contacts and ensured that they are tight?
If you can say you have cleaned everything up, I'd say you are on the hairy edge of ok for a voltage regulator. If not, you need to optimize your system to ensure that you are not reading errors (i.e. poor connections).

BamBam, slight differences in length between brushes is not the major concern (although you might check the slip ring for roughness). You need to ensure that you have at least the minimum service length for both brushes (8.5mm/0.334inches). If they are at all close, get them replaced asap.

 

sorry i ment the short one is 2mm the other is about 10mm

 

i may be in luck i found a donor bike same year but its a 1000 will the parts fit my 700

 

You need new brushes ASAP my friend, give Chacal a jingle.

 

Try testing the regulator using this chart from an XJ550 manual. You will see that there are six diodes giving 3-phase full wave rectification. Possibly, one of the diodes is faulty.

Be careful with the chart as digital and analogue meters work opposite ways around, so this chart is right for an analogue meter and a digital meter on the "Diode test" setting will work the opposite way.



Mods: I hope this isn't too big!

 

new brushes installed working fine now thanks guys