3 Phase Wiring at Rectifier

Hello,

I am replacing the wiring harness on my 73 Commando. The Bike has a 3 Phase conversion and therefore 2 Zener Diodes and the Rectifier is different to standard.

Heres a Photo.



Because the 3 Phase Conversion is not catered for by the original wiring harness i had to add a cable to the harness between the Alternator and the Rectifier. Also i added a Cable to the brown spade connection on the end of the rectifier - this goes directly to the 2nd Zener Diode.

In the Photo you can see on the end of the rectifier the Double Brown (with the aforementioned 2nd zener diode cable). Then on the remaining the connections on the rectifier come the 3 cables from the alternator. The Capaciter is not yet mounted in its original position but is correctly wired up with brown / blue and double red.

As far as i know thats it for the rectifier area...but this leaves me with a free double red at this point on the harness and, a bit further along the Harness, a double white and a green Cable that are also redundant...

Anybody have any idea what these wires are for?

Connect any red cables you find to earth somewhere on the frame, t is also a good dea to make sure that there is a good earth connection between the engine and the frame, as the isolastics can isolate electricity as well as vibration.

timsha said:

As far as i know thats it for the rectifier area...but this leaves me with a free double red at this point on the harness and, a bit further along the Harness, a double white and a green Cable that are also redundant...

Click to expand...

The "double red" would normally connect to original rectifier earth stud(+) spade terminal.

Is that "green" actually a light green/brown? As that, and a double white would normally connect to the flasher relay.

On my other norton (which is 2 phase) the double red is attached to the end of the rectifier - the double brown and the two from the alternator are connected to the side of it.

Does anyone have a working 3 Phase conversion and know how the rectifier should be wired up?

By the way.....What are those two tabs for on the corner of the square plates of the rectifier? Does the double red perhaps come on one of these?

L.A.B. said:

The "double red" would normally connect to original rectifier earth stud(+) spade terminal.

Click to expand...

What happens to this double red with three phase. Is it really redundant?

L.A.B. said:

Is that "green" actually a light green/brown? As that, and a double white would normally connect to the flasher relay.

Click to expand...

Yes it is and the bike has no indicators so thats correct that they're redundant.

This forum has pages of info on all manner of commando problems but the fun is doing it on your own testing your knowledge and capabilities. I find I get most satisfaction working it out by the old books but sometimes it isn't possible and it's handy to spitball!

J

timsha said:

By the way.....What are those two tabs for on the corner of the square plates of the rectifier? Does the double red perhaps come on one of these?

Click to expand...

Nothing would usually connect to those "tabs" in a three-phase system so no, the red is a ground, and doesn't go to either tab.

timsha said:

L.A.B. said:

The "double red" would normally connect to original rectifier earth stud(+) spade terminal.

Click to expand...

What happens to this double red with three phase. Is it really redundant?

Click to expand...

Although there are probably sufficient harness ground connections without it, I'm sure you can find an alternative "home" for it, somewhere?

L.A.B. said:

timsha said:

By the way.....What are those two tabs for on the corner of the square plates of the rectifier? Does the double red perhaps come on one of these?

Click to expand...

Nothing would usually connect to those "tabs" in a three-phase system so no, the red is a ground, and doesn't go to either tab.

Click to expand...

I own 2 Lotus' and owned MGB for many years. They have Lucas alternators. Automobile 16,17 and 18 ACR alternators have rectifier components that are also used on our bikes. In those applications some of the tabs have a function relating to regulator hook ups. Not having to retool for every job is good and the rectifier stampings do serve dual purpose, as is evident here. :mrgreen:

Since it has a 3 phase maybe now is the time to clean up the stock wiring mess and fit a combination rectifier regulator and ditch the zeners and rectifier. Three alternator wires in, positive and negative clean DC out, no mess.

Here's one: http://www.podtronics.net/

JimNH said:

Since it has a 3 phase maybe now is the time to clean up the stock wiring mess and fit a combination rectifier regulator and ditch the zeners and rectifier. Three alternator wires in, positive and negative clean DC out, no mess.

Here's one: http://www.podtronics.net/

Click to expand...

any particular reason there isn't a 3phase battery eliminator type"

can the POD-3P THREE PHASE be used with the stock or other capacitor?

Boyer makes a 3 phase with a built in capacitor:

http://www.boyerbransden.com/PBdynamo.html

This link may help: https://www.oldbritts.com/17_333131.html

I went from stock to the 3-phase Lucas Powerbase alternator kit many years ago and just last month converted to 3 phase POD. Nothing was wrong with the Powerbase setup but I wanted to clean up and undo some stupid things I did to my wiring when in my early twenties and added to over the years. Also put in a small fuse box to get rid of all the extra fuseholders hanging around for my horn, lights and ignition relays.

For the 3 phase rectifier, the green-yellow and green-white are connected to 2 of the 3 smaller lower terminals respectively. They have you run a solid green wire to the rectifier from the new 3rd stator wire. This goes to the 3rd small terminal. The hot (-) brown-blue wire goes to the large top terminal on the rectifier. The rectifier is connected to ground on the bike (red) via its mounting stud.

When converting, I noticed the new brown-blue wires that had been supplied with the Lucas kit are heavier gauge than the stock wires. This is a probably a good idea. You can use the 2MC blue capacitor with either setup but I eliminated mine and put the fuse box and POD in its place.