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Discussion Starter · #1 ·
Hey all,

I have a 85 CB450SC Nighthawk. Previous charging issues were solved by a new regulator/rectifier and all was well for several months. Headlight on/off was about 14v. The battery is a WPS lithium.

However recently, I would come out to a bike with a dead battery. It seems there is some drain on the system while it sits. I would charge the battery, the next morning it will be dead. If I charged the battery and let it sit, it held 13.3 volts for days. Connected to the bike and running, it would read 13.6 volts with the headlight on, 13.8 volts with the headlight off. Left it sit in the bike a few hours and came back to it reading 12.8.....was able to start the bike, and "charging" it would read 12.8, but would not come up.

Does this sound like a battery issue? Like I said it will maintain a charge out of the bike, but once connected could there be an internal draw in the battery?

Or does it sound like it needs another regulator/rectifier? There have been no changes to the wiring on the bike, I have checked all connections but have found no problems.

Lastly, do the 3 yellow wires to the stator require a specific connection or is any order connection acceptable?

The green wire from the regulator is connected to battery ground, the red to battery positive, the black was capped and not used even with the previous regulator install..

The fact that it was working before makes me think the current connection is not the issue.

Thanks for any guidance!!
 

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Your wiring is correct, the Yellow wires dont' have any order to them. The charging system will function better if the Black wire is reconnected to the harness like Honda designed it. That's a load sense wire the changes the charge rate some when a new load is added to the system, like the brake light on.
To diagnose this problem charge the battery and install it leaving the negative cable off. Set your VOM to volts and connect the leads to the negative battery terminal and cable. You should read zero volts w/key off. If there's any voltage reading then there's a draw on the battery draining it. Look at the wiring diagram and identify every component that is receiving power from the Red wires coming from the positive battery terminal. Disconnect each component one at a time and check your VOM. When the voltage drops off you've found the culprit.
 

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Discussion Starter · #3 ·
Will do, but what's odd is it also doesn't seem to charge while riding now. I had to push start it today. After a 25 minute ride home still dead. It's like it will maintain the charge it has but not add any back. I disconnected the regulator from the battery and with the volt meter connected to the red wire from the regulator only and the other to ground I am only reading a 2.5-2.8 volt output?
 

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I'm quite willing to bet $$ that the voltage regulator has died. Been there and done that. By disconnecting the regulator you also disconnected any charging path to the battery.
 

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Discussion Starter · #5 ·
Long, you were right! Unfortunately the previous electrosport regulator I bought only lasted a few months. Just installed a new Ricks Regulator Lithium compatable and all is well again at 14 volts. Thanks for the help.
 
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