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3 wire /2 wire alternators??? #634952
01/13/16 10:55 am
01/13/16 10:55 am
Joined: Apr 2007
Posts: 528
Southeast Usa
B
Bigtwin Offline OP
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Bigtwin  Offline OP
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Posts: 528
Southeast Usa
Hi!
Please help me through another "senior moment"!!! I am working on an early Interceptor fitted with a 3 wire alternator going in to a "2 wire" main harness... It is producing ridiculous amounts of unrestricted voltage. Seems like I remember (ha!!!) a remedy for such situations as tying 2 of the 3 wires together resulting in the opposing magnetism of counter wound coils reducing the output... Does it matter which color wires are tied together, or am I back to try it and trouble shoot? The bike evidently lived like this for quite a while, with every bulb "very" blown! I know, easier to find a 2 wire alternator, but...

Regards!

Bigtwin


Last edited by Bigtwin; 01/13/16 11:26 am.
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Re: 3 wire /2 wire alternators??? [Re: Bigtwin] #634971
01/13/16 2:02 pm
01/13/16 2:02 pm
Joined: Aug 2001
Posts: 7,602
scotland
triton thrasher Offline
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triton thrasher  Offline
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Sounds like the Zener diode is missing or disconnected or has gone open circuit.

It regulates voltage.

There are handy combined rectifier/regulators available too.


Amateur Loctite enthusiast.
Re: 3 wire /2 wire alternators??? [Re: Bigtwin] #635090
01/14/16 8:34 am
01/14/16 8:34 am
Joined: Feb 2009
Posts: 205
London, England
Triumph5ta Offline
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Posts: 205
London, England
Yes, sounds like regulator (zener diode) gone bad or not connected.
This is what I would do:
Buy a modern combined regulator/rectifier such as a "Podtronics"
Remove the old rectifier and the zener diode.
Join the green/black and the green/yellow wires from your alternator together.
Connect these joined wires to one of the yellow wires going to the Podtronics.
Connect the green/white from your alternator to the other yellow wire from the Podtronics.
Black from Podtronics to negative on the battery
Red from Podtronics to positive on the battery

You now have regulated and rectified current to the battery AND! .....
12 VOLTS!
So you need to replace all bulbs with 12v ones.
You will also have some redundant wiring if you have the old wiring harness. You can tuck this out of the way but make sure you insulate any unused ends before you do.

Last edited by Triumph5ta; 01/14/16 8:37 am.
Re: 3 wire /2 wire alternators??? [Re: Bigtwin] #635093
01/14/16 8:56 am
01/14/16 8:56 am
Joined: Aug 2001
Posts: 7,602
scotland
triton thrasher Offline
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triton thrasher  Offline
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scotland
I'm assuming that "ridiculous amounts of unrestricted voltage" means more than 15V.


Amateur Loctite enthusiast.
Re: 3 wire /2 wire alternators??? [Re: Bigtwin] #635174
01/14/16 8:13 pm
01/14/16 8:13 pm
Joined: Dec 2008
Posts: 207
Rossland BC Canada
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Chris Overton Offline
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Rossland BC Canada
This is an early Interceptor. If a '64 or '65, it may have 12V with a Zener on a plate under the toolbox. But, odds are it was supplied as 6V with the complicated ignition and headlite switches (S86?) to connect the 3rd pair of coils when the lights were turned on. Voltage control was crude - draining the charge in the battery or boiling the electrolyte, depending on how charging balanced with connected load. Either way, the cure is the already mentioned regulator/rectifier. Tympanium is another brand I have used successfully. If the complicated switches are giving grief after 50 years and you cannot find terminals that will give you the simple on/off function you need, new switches and rewiring may be in order. I am facing the same dilemma with a Continental GT converted to 12V way back. The switches are a continual source of grief when wet.

Re: 3 wire /2 wire alternators??? [Re: Bigtwin] #635185
01/14/16 10:23 pm
01/14/16 10:23 pm
Joined: Jan 2005
Posts: 981
Ontario Canada
Don Leaming Offline
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Don Leaming  Offline
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Posts: 981
Ontario Canada
My 66 S1 Interceptor and current 65 Interceptor were both 6V when I got them.


1965 Royal Enfield Interceptor
1969 Triumph Tiger 650
Re: 3 wire /2 wire alternators??? [Re: Bigtwin] #635188
01/14/16 10:56 pm
01/14/16 10:56 pm
Joined: Sep 2013
Posts: 1,733
Pacific northwest
Q
quinten Offline
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quinten  Offline
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Posts: 1,733
Pacific northwest
Originally Posted By Bigtwin
Hi!
Please help me through another "senior moment"!!! I am working on an early Interceptor fitted with a 3 wire alternator going in to a "2 wire" main harness... It is producing ridiculous amounts of unrestricted voltage. Seems like I remember (ha!!!) a remedy for such situations as tying 2 of the 3 wires together resulting in the opposing magnetism of counter wound coils reducing the output... Does it matter which color wires are tied together, or am I back to try it and trouble shoot? The bike evidently lived like this for quite a while, with every bulb "very" blown! I know, easier to find a 2 wire alternator, but...

Regards!

Bigtwin

not enough information is given to help ?

it sounds as if half the bike is 12volt and half 6 volt ... some sort of incomplete conversion was attempted ?

6volt systems used switching to control coil output to expected lighting loads ( with mixed success )
but 12 volts systems either dump excessive voltage as heat though a zener
Or
Ac shunt the stators output to match a voltage set point .

.

Re: 3 wire /2 wire alternators??? [Re: quinten] #635381
01/16/16 6:22 am
01/16/16 6:22 am
Joined: Jun 2002
Posts: 10,239
Scotland
S
Stuart Online content
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Stuart  Online Content
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Posts: 10,239
Scotland
Originally Posted By quinten
not enough information is given to help ?
it sounds as if half the bike is 12volt and half 6 volt

confused shocked

Ye-ea-ah, right ... cool

Re: 3 wire /2 wire alternators??? [Re: Bigtwin] #635384
01/16/16 7:12 am
01/16/16 7:12 am
Joined: Jun 2002
Posts: 10,239
Scotland
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Stuart Online content
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Stuart  Online Content
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Scotland
Hi,

Originally Posted By Bigtwin
early Interceptor fitted with a 3 wire alternator going in to a "2 wire" main harness

Firstly, please forgive any slight vagueness, I'm familiar with Lucas electrics on Triumphs and BSA's, not so much with RE's; however, Lucas supplied RE with pretty much the same at the same time as they supplied Triumph and BSA.

Secondly, what you're asking are separate questions, and you've mixed up bits of information.

Before about 1969, Lucas only supplied three-wire single-phase alternators for motorcycles; so the '"2 wire" main harness' is '69?-on and the two wires are Green/Yellow and White/Green?

Otoh, if the "3 wire alternator" is original Lucas, it has a Green/Black wire in addition to the aforementioned two colour combos.

Unfortunately, Lucas used the same wire colour combos. for two completely-different stators ... whistle ... During the 1960's, Lucas supplied the RM19 and RM20 single-phase; from 1978, they supplied the RM24 3-phase ... aftermarket as well as o.e. So it's as well to establish which stator the bike has; if you can find the 5-figure number on the stator, that'll tell us; or look inside the inner circumference of the stator for the ends of the coil cores - single-phase have six, 3-phase have nine.

Originally Posted By Bigtwin
tying 2 of the 3 wires together resulting in the opposing magnetism of counter wound coils reducing the output

Nope.

Only when the electrics were 6V, in order to regulate the output of the stator coils, Lucas did some complex switching through the rotary switches (usually PRS8 or 88SA) they also supplied. But 'fraid what you've posted is gobbledegook ...

Originally Posted By Bigtwin
Does it matter which color wires are tied together,

Only if the "3 wire alternator" is single-phase (RM19 or RM20), you can connect the Green/Black to the Green/Yellow; the White/Green remains separate all the way between stator and rectifier. Typically, this was done as standard when Lucas/the bike makers switched from 6V to 12V, when a Zener diode was also incorporated in the harness for regulation, so the complex connections through the rotary switches were deleted ... Lots of changes between 6V and 12V ...

Originally Posted By Bigtwin
easier to find a 2 wire alternator,

Not necessarily. Depends what you're trying to achieve - 6V or 12V electrics (if 6V, a 2-wire stator is little use to you) - and the electrical parts - harness, switches, etc. - you're working with.

And the bike's exact year ... wink

Hth.

Regards,

Re: 3 wire /2 wire alternators??? [Re: Bigtwin] #635386
01/16/16 7:25 am
01/16/16 7:25 am
Joined: Aug 2001
Posts: 7,602
scotland
triton thrasher Offline
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Posts: 7,602
scotland
Just to make things worse, I think some early versions of 12V kept the coil switching "regulation" as well as having a Zener. Nortons?


Amateur Loctite enthusiast.
Re: 3 wire /2 wire alternators??? [Re: triton thrasher] #635392
01/16/16 7:57 am
01/16/16 7:57 am
Joined: Jun 2002
Posts: 10,239
Scotland
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Stuart Online content
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Stuart  Online Content
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Posts: 10,239
Scotland
Hi,

Originally Posted By triton thrasher
I think some early versions of 12V kept the coil switching "regulation" as well as having a Zener.

Are you thinking of the "2-stage charging", when the four stator coils between Green/Yellow and White/Green were normally is use, with the two coils between Green/Black and White/Green switched in when the headlamp's turned on?

If so, the connection between Lighting Switch pin 4 and White/Green isn't present, so there isn't any short-circuiting of the two stator coils when the lights are off. As I say, only the connection between Lighting Switch pin 7 and Green/Yellow is present, so it appears to be doing what the more-common connection between Green/Black and Green/Yellow between the stator and rectifier does, just only when the when the headlamp's on.

Hth.

Regards,

Re: 3 wire /2 wire alternators??? [Re: Bigtwin] #635396
01/16/16 8:37 am
01/16/16 8:37 am
Joined: Aug 2001
Posts: 7,602
scotland
triton thrasher Offline
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triton thrasher  Offline
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Posts: 7,602
scotland
I'm thinking of this lash-up.



Amateur Loctite enthusiast.
Re: 3 wire /2 wire alternators??? [Re: triton thrasher] #635410
01/16/16 9:58 am
01/16/16 9:58 am
Joined: Jun 2002
Posts: 10,239
Scotland
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Stuart Online content
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Stuart  Online Content
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Posts: 10,239
Scotland
Hi,

Originally Posted By triton thrasher
I'm thinking of this lash-up.

Yep, same beastie. Because Green/Black is connected to pin 7, Green/Yellow is connected to pin 5 and pin 5 is connected to pin 6 internally, Green/Black and Green/Yellow are only connected together when the switch is in "'H' POSITION".

Otoh, when you have the 6V regulation-by-magic (magnetism), White/Green is additionally connected to pin 4.

Fwiw, I suspect Norton only connected the two stator coils between Green/Black and White/Green 'all the time' because the ignition was magneto - no ignition coil(s) to draw on the battery. Otoh, I suspect Lucas drew the "2-stage charging" with the four stator coils between Green/Yellow and White/Green connected 'all the time' because the RM19's output is pretty feeble when regulated for 12V. frown

Hth.

Regards,



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