Alternator overcharging

baz

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Recently I bought a 1992 royal Enfield bullet 500
It's overcharging ,it goes up to 17 -18 volts at the battery when I checked it
The alternator it has is the 3 wire type with two joined together
I have tried to fit a Japanese bike (Honda) reg/rectifier this unit has the 3 yellow wires (alternator input) it has a red live (goes to + on battery) and a green ( goes to - on battery) and a black wire that connects to the red after the ignition switch
It dosent charge unless I disconect the black wire
When I do this it doesn't regulate
I have a reg/rectifier on order this is a "Swiss" type one I'm wondering if this will work with my bike because after I googled royal Enfield bullet alternators most of them are a 4 wire type?
I should point out my bike is negative earth 12volt
And at the moment it has a standard reg rectifier fitted unlike the later version that has two separate units
At the moment it's ok with a halogen bulb headlight turned on all the time but I need to know the best way to sort it out
Cheers
 
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I tried to understand the 4 wire Alternator and gave up, it used part of the alternator for charging the battery and feeding DC to the ignition and the other part stayed as AC and fed the lighting. Could the harness still be configured for the 4 wire system and so making the reg/rectifier not regulate.

This may help

Fit a Japanese Regulator Rectifier Unit to a 12v AC/DC Royal Enfield Bullet

https://www.instructables.com/id/Fit-a-Japanese-Regulator-Rectifier-unit-to-a-12v-A/
 

baz

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I tried to understand the 4 wire Alternator and gave up, it used part of the alternator for charging the battery and feeding DC to the ignition and the other part stayed as AC and fed the lighting. Could the harness still be configured for the 4 wire system and so making the reg/rectifier not regulate.

This may help

Fit a Japanese Regulator Rectifier Unit to a 12v AC/DC Royal Enfield Bullet

https://www.instructables.com/id/Fit-a-Japanese-Regulator-Rectifier-unit-to-a-12v-A/
If it was configured for the 4 wire alternator then it would have been so from brand new
In that link you sent it states that a Japanese type regulator will only work with the 4 wire alternator?
I just can't see why?
On my commando I have an Alton single phase 2 wire alternator and I fitted an identical honda regulator to that connecting to 2 of the 3 yellow wires and it works fine
After saying all of this I noticed when coming back from work the ammeter was reading lower and when I checked it it is now charging at just over 14volts with the lights off!!
It was 18 yesterday!!
I must have disturbed a wire when I re connected it?
I have somewhere a Boyer powerbox I was thinking about trying
Cheers
 

baz

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I was wondering if it needs to be a single phase regulator for some reason?
Or if I disconnected the the two bridged wires from the alternator and connected all 3 to the 3 yellow wires on the Honda regulator ?
 
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I have used a 3 phase rectifier on a single phase bike and just connected 2 of the 3 yellow wires and it worked, the 3rd yellow was unconnected but could be used if one of the other yellow wires failed.
 

baz

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I have used a 3 phase rectifier on a single phase bike and just connected 2 of the 3 yellow wires and it worked, the 3rd yellow was unconnected but could be used if one of the other yellow wires failed.
Yes that's exactly what I was trying but it won't work on this Enfield
Cheers
 
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Regulator not functioning correctly – you might want to get in touch with the spark at Motorcycle Techniques at Clapham, he helped me with my electrical problem.
 
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I was wondering if it needs to be a single phase regulator for some reason?
Or if I disconnected the the two bridged wires from the alternator and connected all 3 to the 3 yellow wires on the Honda regulator ?
I have installed Shindengen Gold Wing R/Rs on a number of old Suzukis I used to use as group touring bikes. I had over charging issues and boiled one battery dry on a coast to coast trip with five of us. Voltage was high due to resistance in the ignition switch circuit, kill switch circuit, fuse panel, and tail light circuit (on whenever ignition switch is on). Subsequently, I have rerouted all of the sense wires to the battery, and have not had any problems with overcharging. "Experts" including genuine electronics engineers, have insisted that the sense wire diodes in the R/R will leak current back to ground through the R/R. In practice, the bike can sit for weeks without that happenning. Your overcharging may be caused by similar resistance in circuits between the battery + connection and the sense wire. Might check the resistance there. If it isn't that, your R/R has likely soiled the bed.
 

baz

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Just a follow up on this
The other day the regulator/rectifier packed up completely, I just about made it home with the lights off
I fitted the "Swiss" reg/rectifier and all is well ,it's indicating just slightly over 14volts when revved with the lights off
Cheers
 
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