Modern Vespa

I'm attempting to see if a new 6v 4-pole rectifier can provide better charging to my (new) 6v battery. My current rectifier cannot charge as fast as my lights deplete it, and I'm not willing to give up driving with the lights on daytime. My scooter is a '74 Rally, wiring diagram below.

My question here is how to work with the single AC in connection of the 3rd party 4-pole rectifier? The rally has 2 yellow stator wire config (outputs 12v AC on both) but the 3rd party rectifier has only one connection for AC in.
Do I;
1) connect them both to the same connector on the rectifier or;
2) ground one, or;
3) just blank one off?

Diagrams below. The second one is for reference only, It's from another scooter, but shows how the 3rd party 6V rectifier is hooked up in that configuration.

I know that this isn't ideal, but before going 12 v battery-less I thought I'd try this. It would be easily reversible and close to stock.

I am assuming you realize you will be losing half of the output of your stator?

I honestly cannot remember the layout of the Rally stator (and am too lazy to go to the garage tonight and dig around for one), but grounding one leg may bump the output of the other to 12V (but sadly not give any extra current).

Connecting them together? No, the phasing of the AC is all wrong.

Leave it insulated.

Let us know how this works, I am curious!

A full wave rectifier/regulator is best used when you have a stator with two yellow wires. If you use the rectifier unit shown in your post you will only have half save rectification of the ac, effectively only half the potential power. If you still want to use it just ground one of the yellow wires, but don't expect much. But is that unit 6v or 12v??

I have a two yellow stator and use a 12v full wave rectifier/reg from trailtech. It was about $50 and works really well. There are cheaper 12v full wave rect/reg available as parts for larger gy6 scooters that should work also.

Good luck

Hi TR & Warhorse,
Maybe I'm reading my own diagrams wrong here. Looking at the first one I suspect that its telling me to attach the yellow stator output wires to the poles 2 & 3 that I marked in blue colour. What do you think?

That's what it looks like to me too. Since you have two yellow wires coming from the stator how about connecting one to 2 and the other to 3. Just my 2 cents.

I don't think your stator is grounded on one end as in the diagram. I THINK your two yellow wires are ungrounded (floating) as they are in P Series two-yellow wire stators.

What they and you said, try attaching the two yellow wires to terminals 3 and 2. Floating AC in from stator.

Attach a wire from the battery to terminal 1. It allows the regulator to "sense" the voltage and the regulated output charges the battery. The regulator will not show output without being connected to the battery. Should be over 7 volts. The battery must be good and not discharged.

Ground terminal 4 to metal and/or the negative side of the battery. Good luck.

Was that diagram provided by the seller of the aftermarket regulator?

To verify sufficient output on the two yellow wires, a 6v 1154 tail/brake lamp in a 12v 1157 brake/tail fixture will work as a test load. It should burn both filaments with the engine running. A 12 volt 1157 should glow if an 1154 is unobtainable. You cannot fully trust a voltmeter reading on an unloaded stator.

Maybe that'll work. According ti the diagram you'd get regulated ac from one wire for your headlight and rectified dc for charging the battery from the other.

No, that reg won't give full wave output no matter how you connect it, it's a half wave rectifier. The white wire should come from the stator to pin 2 and control the DC out of pin 1.

Hi again,

Just tried it during lunch, it works (!), just as well as the standard regulator.
Both yellow 12v AC cables from the stator connects to it, 1 pole to ground, one to the same 6v circuit. Photo below.

Problem is that it outputs the same amount of voltage as the old regulator, between 6.1 and 6.3V. This is apparently not enough to keep up with me using the headlights all the time while running, which is what I want to do. I suspect that if one ran the scooter using the lights only at night it would work, but I'm not willing to do that.

Thank you everyone for your input, I really appreciate it.

The diagram you posted earlier was for an AC regulator + half wave rectifier but the reg you have looks like a 12V full wave DC type.
When you connected it up, did you connect the other stator wire (white)??
If you did then you would only get 12V half wave which your meter will measure as about 6v.
If it is a DC reg you could use it to simply convert your machine to 12V.

That is a full-wave rectifier. The fact that the AC stator output of the original bike that it is from has one side tied to ground does not effect the type of rectification.

Try grounding one yellow wire to the chassis and attaching the other to pin 2. Ground pin 4 and run pin 1 to the positive on the battery.

The regulator/rectifier I bought is supposed to be a 6V unit;
http://www.ebay.com/itm/370625009017?item=370625009017&viewitem=&sspagename=ADME:X:RTQ:MOTORS:1123&vxp=mtr

Then the best your going to get out of it, DC wise, is half wave and as TR says "only using half the power output of the stator".
If you were adamant on using it you would need to run main lights from the AC side of it, and just have the horn, indicators and brake light off the battery.