Charging problems 85 Cb 650 | GTAMotorcycle.com

Charging problems 85 Cb 650

Knight

Well-known member
Ok so it seems like my 85 cb650 does not want to charge (voltage not going above 12v) I did resistance test on my stator and compared that to other cb650s at a local shop/salvage yard and it was the same as the other three so the owner said it's likely not the problem.
Next the reg/rectifier I have borrowed one (he believes it's good) and still no charging when he opens monday Ill try another reg/rec and if that's not the problem I'm lost.I'm going to check the ignition switch next because I read that a bad connection their can cause charging issues.
 
Have you added or upgraded any electrical accessories or is there anything that might be drawing more current then it is suppose to? You could maybe remove fuses one at a time and monitor for a change if your bike has multiple fused circuits. Bad grounding is a far more common issue then almost anything else, particularly in view of the bikes age. Try doing resistance checks between all of your lights and the battery ground as well as an engine ground, the resistance should obviously be zero everywhere, check the horn or even unplug it and see if the voltage increases to the battery, horns draw way more power then most would expect. Indeed it is the voltage regulator that controls the DC voltage output but if your battery has a problem your voltage might never rise above the 12vdc, I would try putting the battery on a smart charger (one that indicates charging/save mode/charged) let the battery sit for 12 hours, reconnect and see if it has lost significant charge to the point that it goes back into charge mode again.

... just took a real quick look at a wiring schematic that 'might' be the correct one for your bike, the battery outputs directly to a solenoid switch where the main 30 amp fuse appears to be located :/ that is suspect, test the voltage at both the battery and the output from that solenoid, it must have some contact points in there and they might be creating resistance. The solenoid is probably in there to facilitate a kickstand safety cutout and kickstand switches are a high failure point on any bike because of their location and exposure to the elements.

Hope this helps some, electrical problems are hard to diagnose remotely and you will probably get more questions then answers.
 
That bike has an unusual 2 piece alternator rotor.
You should likely track down a service manual for the specs, it may be demagnetized and causing a problem.
Ran into this a couple of years ago with an FZ600, it was very hard to track down.
 
Check for crappy connections. That savage I fixed was all do to bad connections. Sand paper and electrical grease fixed it.
 
What RPM are you checking the charging voltage?? Hondas in the 80's were notorious for not putting out any voltage until revved about 1500-2000 RPM. Had an 84 Nighthawk 650 that did not charge until revved
 
What RPM are you checking the charging voltage?? Hondas in the 80's were notorious for not putting out any voltage until revved about 1500-2000 RPM. Had an 84 Nighthawk 650 that did not charge until revved

i'm checking it at over 3k
 

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