rectifier bench test

does anybody know how to test a rectifier, a new stator did not do the trick, electrical is not my thing, battery is good and so is the regulator,thanx:sign67:

I'm not sure if a rectifier for your bike is discrete components or not. If they are then the parts that do the rectifieing are diodes. They are usually black with a grey ring around one end. You can use an ohmmeter and check for continuity both directions. They should pass DC one way but not the other way. If it is a sealed box then this doesn't apply.

Actually, it does apply. But before you test the rectifiers, did you inspect the stator to regulator plug for burnt wires?

Disconnect the negative battery cable, and then disconnect the stator to regulator plug. There are 6 rectifiers in the regulator and if one goes bad the output of the charging system is greatly reduced. Ground 1 lead of an ohmeter (an conventional ohmeter on the RX1 range is best for this test, but a digital ohmeter on the diode test range will work---the normal digital meter ohmeter range will not work). Then take the other ohmeter lead and measure to each of the 3 wires in the regulator side of the stator to regulator plug. Notice if the meter reads about 2/3 scale or stays near the bottom. Then exchange the ohmeter leads and repeat the test. Now the meter should indicate the opposite condition that it did the first time. All 3 leads should measure the same though. Remember that a rectifier conducts in 1 direction, is open in the other. Now move the ohmeter lead to the positive battery terminal and test the 3 leads again. Last, exchange the ohmeter leads and repeat the test. Once again 1 was should indicate 2/3 scale, and the other way open and all 3 wires should act the same. When my regulator went bad, 1 rectifier was open.

The regulator also has a shunt regulator. The stator makes the same amount of charge current no matter what you need. The shunt regulator makes heat out of any extra output and allows exactly what you need to go to your battery and motorcycle wiring. The shunt regulator is dificult to test, but I guess if your 6 rectifiers are OK and also you stator plug isn't burned up AND your new stator is good.......Run it about 2-3000 RPM for a couple of minutes and then touch the regulator and see how hot it is. BTW, are you sure your battery is good?

Read each of the 3 Phase AC wires at the Plug between the Stator, and Rectifyer !!

Post the Voltage readings. They should all be same on each wire, Within + or - 1 Volt AC.

The with enging running, use volt test meter, to read the DC voltage on battery terminal. Should be 13.8 to 14.2 V, DC

Check your Main Ground Cable, where it connect to engine crankcase. Remove Bolt, and Clean it, and the cable Stud. ( Resolder Stud to cable end also good idea )

Is your battery fully Charged ???? With a real battery charger, NOT a trickle charger. Disconnect ,and fully charge the battery before you assume that something else is wrong with the bike !!!

--- Charge at 2 Amp rate for 6 to 10 hours, Be sure to make sure water level is over the plates !!

If its a Sealed Battery and over 3 years old, its probably Junk!!! ( If water is below plates, -- even if its a sealed battery --- its toast !!!