Info Manual

Motorcycle Voltage regulator protects the battery from overcharging by shunting the coil winding, that is why it is an important part of any motorcycle electrical. Replacing a defective unit is a trial and error process if u will be using an aftermarket one and not the OEM replacement.

This post is not against aftermarket but why in the world a friendly motorcycle shop offer a regulator like this. Costumer ask for one, seller gave this part, of course the buyer would not tell the difference between a good and a bad one, i'd say really a BAD one, a FAKE voltage regulator in a well formed housing. (sad).

Out from curiosity, a friend of mine who have a HONDA wave wanting his charging system be converted to full wave system to accommodate the High Intensity Discharge lighting installed. He decided to buy a full wave regulator from his friendly motorcycle part store. I was confused when i test for resistances between pins and only found two pin with resistance. And since i build regulators for motorcycle, i knew there is wrong his unit, that instead of using it, i installed my prebuilt one and enjoy using his HID.
As part of understanding voltage regulator, i opened the regulator. Patience if u want the board intact, hard headed mode if u want it dispose after opening.
Left is the problematic voltage regulator. This regulator will be left destroyed unlike from my previous post here FULL wave regulator that i need the board intact and replicate it. From the very first smash of my flat screwdriver on the aluminum casing, I already know it is FAKE!!! no circuit board.

Moving on, I also noticed bits of sand, What the heck? Sand inside the unit, hmm (at the last of this page i'll tell you the purpose of that sand.)

No circuit board is found on the connector side, All you can see is on the photo.

DIODE. yes only diode soldered on two pin, other two pin not connected, so that is why i  only get one resistance from all the pin available. Too bad. If this unit was place and use on board your motorcycle. Lots of thing may happen, One can overcharge your battery, boil the plates and spill out electrolyte that will cause corrosion on chassis and metal of your bike. Two is overvoltage within your entire electrical system, bust the lights, a defective igniter, and worst, Fried wiring harness.

So as part of educational purposes, Be aware of fake voltage regulators, buy from a reputable store or online products, and do buy a branded one.

CONCLUSION:
The sand was placed inside the fake regulator for one purpose only. WEIGHT. the regulator without any circuit board and just diode will weigh less and may be very noticeable by the buyer. (clever idea huh!) but you cannot fool the ones who know to use the resistance meter. (take that!!!)

RECOMMENDATION
use multimeter and test all possible pin available with the probe, if u get one resistance from all the pin, it is likely to be fake. Just don't plug it in your motorcycle electrical system, test it on the bench.

Not all motorcycle regulator are created equal. This article will tell you how a fake regulator looks like if dismantled. From the housing you will never tell, but what is inside shall tell the difference between a good and a really bad one. From the time it was handed over to me by a friend to look at it. Even i was not sure it was faked. From this post Voltage regulator you wont see the difference externally, they are almost identical, the weight and the appearance, but.....

Bad regulator

Good working regulator

If they are taken side by side, they are identical. Now let us tear down this fake regulator and compare it to the one i posted before and let us see what was inside.
More photo of the said fake regulator properly filled with epoxy resin. Nice job.. It is time to dismantle you. Using my handy dandy mini blow torch and flat screwdriver,
I stripped an area to get down the bottom of it, but to my surprise, the flat screw driver gets punched down easily and here is what happened. White Sand comes down pouring out of the hole made by the screwdriver.
Another photo of this BEACH filled regulator.

From here, I know already what was inside this fake regulator, I already posted one here fake regulator 4 pin

Digging down what was started

After minutes of heating up the epoxy resin and stripping with the screw driver. Here is what inside. A DIODE, yes a rectifier diode

the half of the diode is left inside, take a closer look

A good working motorcycle regulator must have a board and other components aside from a diode.

There are four wires coming out from this regulator and all wires must not have a continuity if test by a multimeter. The green wire and the pink wire on this fake regulator are connected with each other, to which in a good regulator, are separated to other circuitry.

Closer look. So I advice to take precautionary measure of dealing with such kind by using continuity tester. If not familiar with it then bring someone with you when buying motorcycle part like this from your friendly store..(are they really friendly or just taking away your money).

CIRCUIT DESCRIPTION

The circuit is straight forward, It is not a shunt regulator, but a SERIES type of voltage regulator. D1 to D6 comprises the RECTIFIER diode which converts the AC generated by the 3 phase stator, Q1, Q2 and Q3 as the switch that controls the flow of voltage and current to charge the battery, Q1 and Q2 must be heatsink, since this type of regulator is in series mode, and no shunting will happen on all the windings, thus LOAD is particulary important on this kind of regulator.
IC2 inverting input has a two resistor in a differential way thus R4 and R5 is very critical on this design so the value must be at least 2% tolerance. When the IC2 input sense a high voltage, it switches ON Q4 and immediately allow it to control those power transistor flow via Q3, the circuit in RED is like a faucet that controls the flow of water. The circuit in GREEN are the voltage sense circuitry, and The Blue box is the source voltages with the rectifying diodes.