Topic: Electrex Regulator/Rectifier came in today......

[CETME]

Well, the Electrex RR came in today... and its a nice piece! It looks of high quality, and best of all, its made in Argentina (where I was made too!)

Unfortunately when I hooked it all up, started the bike, and tested the Battery, I was only getting 12 volts to the battery, regardless of RPM.

Testing the field coil, (green and white wires) I get a resistance of 5.4 ohms.... above the 4.6-5.0 ohms listed in the clymer... but not too bad I think...

Then the stator, between each of the yellow wires I get 1.0 ohms of resistance between all of them.... clymer and haynes list 0.35 +/- 10% ....

I'm thinking the stator might be bad, since its not very close to the resistance listed.....   What do you guys think?

[TwoTired]

.35 ohms can be difficult to measure if the instrument isn't sensitive enough.  Just the lead resistance in the probe wires can add significantly the such a small reading.  What is the resistance measured when you simply put the probe tips together?  Is it zero?  If not, subtract that from whatever reading you measure on the stator.

Usually the stator failure mode is to open or short to the casework.  If they change resitance due to winding insulation breakdown from over hearing, it would lower the resistance, not raise it.

Did you check that none of the field or stator windings are shorted to the casework?

[CETME]

I tested each yellow wire to ground, but didnt get any continuity... so I dont think any of the stator coils are grounding....

[the_genrl]

...which is good.  the ground connection is made after the rectifier. 

as for the resistance, i agree with twotired.  Its hard to diagnose a stator problem by just going by resistances, mainly beucase of the accuracy of the test equipment. 

I would gather DC voltage readings at different rpms right after the rectifier. (being sure that the rectifier is good first.  your multimeter should have a diode testing setting.)

[oldbiker]

It's also worth checking that all the connections from the field and stator are clean and tight as any high resistance connection will cause voltage loss.

[CETME]

I've cleaned all the connections with a small file, and then with electrical connector cleaner.... then I greased them with dielectric grease.....


Should I check the voltage between the black and white wires going to the "regulator"

[TwoTired]

The black wire is +12 v and should be present whenever teh ignition switch is on.  If you connect this to the White wire of the alternator, it should make full field strength.  The alternator's output will increase with engine RPM.  The stock regulator puts a 10 ohm resistor in series with the filed coil, reducing the field strength and thereby the alternator's output when it perceives the battery voltage greater than 14.5 or 14.7 Volts DC.

You can also measure the AC voltage across any two of the yellow wires from the alternator.  You should do this while it is connected to the rectifier.
The Green and Red/Wht wires are the output of the rectifier which should be DC voltage.

Please report what you read on the black wire, the Red/Wht wire, and the yellow wires when the bike is idling and when it is turning 3K RPM.

[CETME]

Whats the best way to check the yellow wires if the regulator is connected? would I stick pins to pierce the insulation, and touch the wire, then measure across the pins? Or just try to stick the Tester leads behind the connector and try to touch the back of the spades?

[TwoTired]

I suppose the best way would be to make a male/ female breakout device and insert that between the two connectors.  Piercing the insulation to get at the wire within should work.  The disadvantage is that the hole left behind allows for future corrosion.  If you can reach the terminals behind the connector with your probes or pins, that should work, too. 

[CETME]

I checked AC voltage between the yellow wires...... I got 7.4 7.6 and 9.8  volts

Does this mean the stator is toast?

[Bodi]

If everything else is known to be good, those voltages - at 3K+ RPM with the rectifier connected and the field getting full battery voltage - would indicate a bad stator.
Check the rectifier first though. A single bad diode will give bizarre voltage readings.
Try measuring voltage with the rectifier yellow wires disconnected, you should see a fairly high AC voltage (50V?) but the same (within a few volts) on all 3 coil sections.
Make sure that the field coil is getting good power, don't rely on the regulator - connect directly to the battery. Check all connections in both coil's wiring.
The coils are pretty bulletproof, I've found bad rectifiers and regulators and many bad bullet connections causing charging problems - and only one bad coil (which had been ground off in a crash).

[TwoTired]

I checked AC voltage between the yellow wires...... I got 7.4 7.6 and 9.8  volts

Does this mean the stator is toast?

Well, that's not good enough to charge the battery. Duh!  It needs to be about double those numbers.  However, the stator can't put out power if the magnetic field is weak or too low.  The rotating element in the alternator is magnetized by the field coil.  When you measured those voltages it is important to know at what RPM the motor was spinning and what voltage was being applied to the field coil.  Whenever, the battery voltage is under 13 volts-ish, full battery voltage should be applied to the feild coil.  Since you have already measured the field coil resistance and found it out of tolerance and on the high side, this would cause reduced current to flow through the field with a corresponding loss of magnetic field strength.
My 74, however measures 6 ohms on the field.  It still charges the battery, though, if you rev it enough.  I have been driving it this way for years.  I have a replacement field coil to replace it, when I get around to it.

[CETME]

Well... I had an interesting few days..........

I finally got the bike to produce electricity.. but not by replacing any new parts.....   I went ahead and checked a few things recommended to me by Two Tired.... In the first position on the ignition switch, I would get 12 volts to the black regulator wire, and have power to the starter motor, as the bike would crank, but not fire......  The lights and the ignition is off in the first position....

THe second position of the switch activates the lights and the ignition system, but the starter motor and the charging system seems to be offline.....  scratching my head in confusion, I decided to replace the ignition switch..... but it fixed nothing.....  I was stumped, and really at my wits end on the bike, as I'm supposed to be gone already, and this bike is running reasonably well, but is not charging...

after staring at the wiring diagram, and testing which wires become active in the different switch positions, I decided to bridge the Brown wire (this is one that connects to the ignition switch) directly to positive, in the first position...... lo and behold... lights came on, and the bike fired over... and produced 13.8 volts at 3000 rpms!!!

Turning on the high beams burnt the 5 amp fuse, ending my fun for the night... but at least I got it to charge...... There must be something awry with the wiring here, because of it not firing, but i'm ecstatic that It finally started operation "properly"

Anyways... anyone ever run into any situation like this before?

I'd really like to thank everyone who helped me out on this... your advice and help was invaluable....