Will a blown regulator/rectifier give off - volts? By FACE PLANT FOR LIFE (Read 2,213 times)

[FACE PLANT FOR LIFE]

So I am finally getting my bike in running order. The only problem is, two of the regulator/rectifiers I had were giving off negative DC voltage into the battery. I swapped them both out to a spare I had and I got positive DC voltage. Shortly after, the new one starting giving out negative DC voltage. What would cause that? Maybe because I don't have the battery connected at the time of me testing it, it blew it?

[Bashan]

Although an AC system can run without the battery you should always hook it up for testing. You want to simulate normal operating conditions to see what your electrical components are doing. Also, the battery acts as a buffer for a system by absorbing and smoothing spikes and drops. I doubt you roasted your R/R but hook up your battery young man!

Are you sure you have your multimeter hooked up correctly and consistently with each test. Negative and positive DC voltage simply means which way the current is running. If you have your multi hooked up incorrectly it will read negative DC voltage. Swap the leads and it reads positive. Make sure you're testing with the black lead on a negative source such as the battery ground. Recheck your system making sure the multi is hooked up correctly and let me know if the voltage reads negative.

[FACE PLANT FOR LIFE]

Yes, I am being very consistent with my leads. If I swap them around so the black is touching the postive and the positive is touching the battery ground, I get a positive voltage. Checking directly from the alternator regulator, I get negative voltage to the battery. I have positive AC voltage going in to the regulator from the stator though, so I think it's toast. Along with the other three I had.

[Bashan]

If your battery is hooked up correctly, if you have your black test lead on a ground source, and it reads negative DC on the red lead then you're right, your R/R is toast. The diodes are gates that allow electrons to flow in one direction. It is possible to have diode failure in a configuration to show negative DC on the red lead. Replace the R/R.

[FACE PLANT FOR LIFE]

I will, but the other three I have fried in the exact same way, where there is negative DC voltage. What could cause them all to fry like this?

[Bashan]

Diodes are one way gates that will only let current pass in one direction. If some of the "gates" experience a large current surge in the wrong direction it ruins them and they essentially become "wires" since they can now freely pass current in both directions. So where is this misguided current coming from? Probably a ground has come loose or shorted. Check the grounds and wires on the battery and stator. If you have a three phase stator (three yellow wires) there should be no continuity from the yellows to ground but continuity from yellow to yellow. If it's a single phase (one yellow and one white), you should have continuity from the R/R ground to the white and yellow.

[FACE PLANT FOR LIFE]

Well...From what I'm thinking, I'm thinking that my voltage regulator could potentially be wired incorrectly. I've kept the same wiring despite the fact that I've switched voltage regulator's three times. Could it be that it is wired incorrectly, or no? Because they all output voltage, but maybe that means nothing. My wiring right now is this i.imgur.com/LEhiLHz.jpg

[Bashan]

That's a standard GY6 AC stator coupler. The white wire should give around 20v AC, and 15v AC for the yellow. Test the white by getting a probe into the white wire terminus and ground the other lead. Positive and negative are irrelevant because it's AC voltage. Use the same method for the yellow. The yellow supplies the headlight and many of the other lights. The white is dedicated to the charging system. The ground wire connects to the structural metal frame. Here is a generic wiring diagram for an AC system:

The R/R pin out in the older manuals has the wrong pin out for a GY6 AC system. It should have this configuration:

Yes, the R/R that you have may have the wrong pattern. Also, for the red lead to register 12v -DC it would have to have a bad ground on the R/R or stator to swap the voltage. I'd use the above diagram and test the grounds for continuity.

[tvnacman]

Jul 22, 2013 20:12:51 GMT -6 Bashan said:

That's a standard GY6 AC stator coupler. The white wire should give around 20v AC, and 15v AC for the yellow. Test the white by getting a probe into the white wire terminus and ground the other lead. Positive and negative are irrelevant because it's AC voltage. Use the same method for the yellow. The yellow supplies the headlight and many of the other lights. The white is dedicated to the charging system. The ground wire connects to the structural metal frame. Here is a generic wiring diagram for an AC system:

The R/R pin out in the older manuals has the wrong pin out for a GY6 AC system. It should have this configuration:

Yes, the R/R that you have may have the wrong pattern. Also, for the red lead to register 12v -DC it would have to have a bad ground on the R/R or stator to swap the voltage. I'd use the above diagram and test the grounds for continuity.

[tvnacman]

See your wires are in the wrong position. Follow Riches illustration.

John

[FACE PLANT FOR LIFE]

I followed the illustration, everything is back together, and the battery is charging! Although we have one last problem...I'm getting 17 volts to the battery at maximum RPM. Is this going to harm the battery?

[Alleyoop]

Is 17Volts with the lights on? If so yes, the R/R is overcharging, It should only get into the 14s volts charging.
Alleyoop

[FACE PLANT FOR LIFE]

Yes, 17+ volts (almost 18) at maximum RPM wit headlight on bright, dash lights on, and brake depressed to engage the brake light, turn signals on, and the horn blaring. Looks like I'm not done having problems...Is there any way I can bring it down without yet another R/R?

[FACE PLANT FOR LIFE]

AND....it's blown. Negative voltage once again.

FUUUUUU*******************************************************************

-_-

Okay, that time I actually had my leads backwards. It didn't blow, but it sure does charge at the extreme

[Alleyoop]

Sorry to say that R/R is not regulating right, I would attempt to order from a reputable dealer and not go for the cheapest R/R you can find. Even though ALL are made in CHINA some Distributors order from more quality controlled factories over there. But it really is a shot in the dark to tell you the truth.
Alleyoop