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Discussion Starter #1
Went for a ride on my Cb450 K3 yesterday and the green wire going from harness to negative battery terminal broke close to the terminal. This resulted in most of the globe's blowing, headlight, both turn indicators, and the turn relay all blew. The motor kept going and it was some time before I noticed.
The question is would this have damaged the voltage regulator?
Any help is appreciated.
 

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I don't remember - do you have the stock regulator, or a newer one? If newer, which? Odds are, the answer is no, but knowing which regulator could change that answer.
 

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Discussion Starter #3
Thanks Rick,
I still have the original Honda regulator with an aftermarket bridge rectifier on this bike. It has been working well so I have not bothered to change over to a more modern unit.
 

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Why not take the opportunity to upgrade?
You're going to need to at some point anyway so why wait until the original regulator fails and leave you stranded on the side of the road?
 

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Probably not, it was effectively out of the circuit because of the broken ground wire, otherwise it would have held the voltage down to the right level.
 

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Discussion Starter #6
Thanks Mike and 76Twin you are quite right I have been putting it of and riding instead of working now might be a good time to upgrade, but I would like to understand what happen first. So I will start the bike and see what happens to make sure it was the green wire disconnected that caused the problem.
Thanks!
 

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Sensei
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The voltage surge that blew the lights was because without the green wire/ground connection, the Regulator had nowhere to shunt the excess voltage which it normally does by grounding out the yellow AC wire....You were "pumping" unregulated, higher voltage into your 12 VDC circuits.....
 

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Reminds Me of some issues we had,back in my Yamaha shop days, with the 125 cc twins. The customer would bring his bike in, all the lights burnt out, horn only worked with the engine running. The battery leads both had snap connectors(the positive had a fuse holder) , unplugging either one(or blowing the fuse) would take the battery out the circuit leaving nowhere for the charging output to go. Take the load off an a/c generator and the voltage goes sky-high(in just a few seconds), zaps every light bulb in the circuit.
 

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Discussion Starter #9
Thanks for the pointers!
Just back from a 130 mile ride with the green wire connected no blown bulbs!
Will upgrade the regulator ...... next rainy day. 😀
 

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Sensei
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Running an extra ground from the unused Green wire found by the flasher module to a clean chassis ground is insurance against this occurring again.....Redundant grounds are not unusual (ask NASA)
 
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Discussion Starter #11
Thanks Steve, sounds like good insurance will do that tomorrow before I ride it again.
 
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