1962 Norton Dominator Battery probelms 6 Volt Zener Diode / regulator Overcharging?

Hi:

I recently got my 1962 Norton 650SS project bike back on the road. She now runs delightfully. However, I think I have a problem with battery overcharging.

I had initially used a refillable type, but decided to replace it with a sealed unit as I noticed the acid levels were lowering at a rather fast rate. The new sealed one lasted for a few hundred miles before I noted the ammeter needle had stopped registering. I checked the battery and the casing had split and the battery was quite hot!

What is confusing to me is that I assumed that my bike (still 6 volt with points, magneto, 3 wire alternator) would have a zener diode / regulator installed somewhere or other. To date I have not located it. Should my bike have one and if so what should it look like / where should it be? Have any of you Norton owners run into similar problems? If so is fitting a modern solid state regulator a potential fix?

I should note that while the wiring does not appear to be messed with, the many sins I have discovered on my bike - commited by a PO - suggest anything (including miswiring) is possible.

Thank you!

Kind Regards,

James

Zener diodes were not used by Norton in 1962. If your bike has stock wiring, you do not have one.
A modern rectifier/regulator would be a good upgrade, and would stop overcharging woes.

Check that your 3 wire alternator is wired factory stock at the triple junction block located just above the rear primary chain case. GY should be connected to GY, GB connected to GB, and GW to GW. The OP may have cross switched the GY and GB which will give more charge.

Your wiring diagram will be found here......

Slick

I should add that I do have what I believe is an original three prong rectifier located behind the battery box. Is this also the zener diode / regulator? Maybe what I need to do is replace the existing rectifier with a modern solid state three prong rectifier / regulator?

Hi Slick:

Ah, very interesting.... I glanced at something in my manual that talks about "increased charging rate", which must be what you describe regarding crossed wires. I suspect my wiring is stock so as you suggest maybe I just do not have a regulator!

I shall go check my wiring and probably shop for a modern rectifier/regulator.

Thank you for your help.

Kind regards,

James

Britstuff said:

I should add that I do have what I believe is an original three prong rectifier located behind the battery box. Is this also the zener diode / regulator? Maybe what I need to do is replace the existing rectifier with a modern solid state three prong rectifier / regulator?

Click to expand...

You have a three prong rectifier. On my Atlas it is mounted under the tool box. It is not a regulator, nor does it have a Zener. I upgraded mine to a Podtronics rectifier/ regulator. It is not the best, but is reliable and relatively inexpensive. I mounted it in the same place as the original rectifier.

Like you, I suffered overcharging with stock wiring. Boiled over battery acid took the chrome off my primary cover and left side silencer.

Slick

Hi Slick:

Ouch! It does sound like I have been very lucky to not suffer similar damage. Now I have done a bit of research, I think I see that for my bike the third wire / higher current wire from the alternator stator is only supposed to be activated if the headlight is turned on, (assuming of course that the wires have not been flipped as you suggested above). Such was apparently the state of the art prior to the implementation of a zener diode / regulator a few years after my bike was manufactured.

May I ask what you have against a Podtronics rectifier/regulator? Is there some other brand that in hindsight you wish you had purchased instead?

As always yours and other information on the forum has proved extremly helpful!

Thank you

Kind Regards,

James

Britstuff said:

If so is fitting a modern solid state regulator a potential fix?

Click to expand...

Very much so! Go 12V at the same time.

A Shindengen is more efficient, but more expensive. If I had my druthers, I'd druther have a Shindengen.

Worntorn removed the only concern I had with the Podtroniics <https://www.accessnorton.com/NortonCommando/stator-heat-test.33913/>
I am quite happy with my Podtronics, and I am sure you will be as well.

As TT recommends convert to 12 V as well ..... simply replace with 12V lamps (bulbs), and 12V battery. Since you have a magneto, you can get by with a small (2.5 AH) battery. I can provide a drawing for a battery holder for one such battery.

You might consider LED's but that gets a bit trickier.

Slick

With those old Lucas alternator on Norton you only have to change two wires over to go from the old 6v to 12v (hence at 12v you need a Zener and heat sink)
Originally you would've have had 2 x 6 volt batteries.

texasSlick said:

Zener diodes were not used by Norton in 1962. If your bike has stock wiring, you do not have one.
A modern rectifier/regulator would be a good upgrade, and would stop overcharging woes.

Check that your 3 wire alternator is wired factory stock at the triple junction block located just above the rear primary chain case. GY should be connected to GY, GB connected to GB, and GW to GW. The OP may have cross switched the GY and GB which will give more charge.

Your wiring diagram will be found here......

Early Norton Wiring Diagrams

Sorry if I duplicate any previous post. My object is to get all early wiring diagrams in one place. Please feel free to make additions. All diagrams are from Norton publications. Wire color codes: B - black U - blue N - brown G - green K - pink P - purple R - red S - slate W - white Y -...

www.accessnorton.com

Slick

Click to expand...

You are right Lucas did not produce the Zener until 1963, however they supplied a booklet no 2380 for a number of machines.
It's a simple job which any home mechanic can carry out converting 6 to 12 volts, there should be lots of previous posts.

Dear All:

Thank you for your incredibly helpful replies. It would seem that converting to 12 volt is the logical way to go!

But.......... as soon as my last battery blew up, I ordered another one. Knowing I had another 6 volt battery on the way, I decided to see if I could get a 6 volt solid state rectifier / regulator. Apparently they do exit, but are not as readily available as their 12 volt brethren. I found one - a few days ago - that I currently have on order.

https://guzzino.stores.yahoo.net/noname3.html

So for now at least I am planning to pursue a 6 volt solution. If things do not go according to plan, then I will likely come to my senses and convert to 12 volt and fit a 12 volt solid state rectifier / regulator.

Kind Regards,

James