Another R/R test question.

[slowride]

I have already determined that I need a new R/R and as soon as it arrives from duanage, I'll install the newer one. Anyway, I came across a test from my GS 850 Manual. It describes how to check for resistance between the wires but my question is, do I have to remove the R/R from the frame to do the test or can I test it as is?

Ed

[doctorgonzo]

If it's the same test in my manual you can do it still mounted. It just tests that current only flows one direction through the diode. Red to red, black to yellow = current. Reversed = no current. I could have that reversed, manual not in front of me, but it's something like that.

[Redman]

No, do not need to remove R/R from bike. But do have to disconnect the wiring.
And you will want to find where the ground (blk/wht) wire from the R/R is connected/grounded, usally under a mounting bolt for the solenoid. Do your test to this point, not just any "ground".

Also see this, about using the "diode test" feature of more modern meters, rather than the ohm check, as described in the stator papers section C (go back to main webpage, look for "in the garage"). Can also look at this other posting relative to the same subject, see what Tomm posted.

http://www.thegsresources.com/_forum/showthread.php?t=123895

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[slowride]

I did the diode test but never got any voltage reading. The only readings I got were OL and it didn't matter which wire I had my + and - hooked up to. I disconnected the R/R for the test. Would that have made a difference? Of course, I could be messing up somewhere else. I was thinking I did not have my meter connected to the correct red wire. I connected to the one I thought was coming out of the R/R.

Thanks for your feedback. I really do appreciate it.

Ed

[Redman]

YEp, meter lead on red wire out of the R/R, and then other meter lead to the other R/R wires one at a time and then the ground wire. And then negitive on Red.... and so on.....

Ah, red wire from the R/R you think. Lets help you verify that.
R/R is located under the battery box (on mine anyway). has 5 wires:
red, yel, wht/blu, wht/red and the blk/wht. Sometimes the blk/wht is seperate from the others wires wire go to a white connector (82 and later I think).

To check to see if meter set up correct (and meter battery good) for ohm check: Touch meter leads together should go to zero or near zero.
Then to check that making good connection of meter leads to wire/connector: put both meter leads on the same wire/connector. May find that you have to kinda grind the meter leads in a bit to make contact.

Also: When you say you are doing the "diode test", you should say weither you are checking the resistance of the diodes with the "ohm" feature of the meter (reads out in zero to many, have to look to see if ones or thousands, or shows "OL" if over the limit as in open or not connection at all), or if you are usings the "diode" check feature of the meter (reads out in 0.0 to 2.5 volts). You say "OL", so I assume you are measuring ressistance (ohms).
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N.E. Ohio, like Ashtabula?
I used to live in Euclid. Just like to say "Ashtabula".
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[tomm]

I know this has been posted before, but maybe repeating here might be helpful.

When you check a diode, you are checking to make sure that it conducts electricity in one direction, but not in the other direction. It conducts when the anode is positive relative to the cathode. (The anode is the end in the diagram with the line across the point of the triangle.) In bike speak, that means when the black lead of the meter is on the red rectifier wire and the red lead is on the stator wire for the top set of diodes, or the black lead is on the stator wire and the red lead is on the ground rectifier wire for the bottom set. Essentially, a high voltage from the stator can push current through the diode to the battery, but not the other way around.

A good silicon diode, which is what is in these rectifiers, starts conducting when they have a voltage across them of about 0.3 volts, and are fully conducting when they have about 0.65 volts across them.

When checking them for resistance, they should read pretty much open when reverse biased. Don't remember what these are for resistance forward biased when measuring them, but thinking maybe 10K - 15K. However, remember that meters measure resistance by putting a voltage across something and measuring the current flow (volts = current times resistance). Some digital meters don't use a voltage greater than 0.3 volts to measure resistance, so they never forward bias the diode. With these meters, diodes read open in both directions. The diode may be good. It's the way the meter works. Use the diode check instead.

When checking using the diode check, the meter measures the voltage needed to start the diode conducting. Reverse biased, it should never conduct. So reads open. Forward biased, as stated above, should be starting at about 0.3 volts up to about 0.65 volts, depending on how your meter reads it.

Best to disconnect the wires before checking measurements, otherwise you can't be sure what other path the test current might be taking and messing up your measurements.

You can measure each of the six diodes one at a time by measuring from each stator wire to rectifier red, first forward biased and then reverse biased, and then measuring from each stator wire to rectifier ground, first forward biased and then reverse biased. So twelve measurements total, two across each diode. Forward biased is 0.3+V diode test and maybe 10K - 15K ohms resistance test. Reverse biased is open for diode test and very high resistance (essentially open) for resistance test.

[slowride]

Well, I'll be honest. I don't know what diode I was testing. I was trying to follow the directions in the Stator Papers IV, Test Phase C. I put my multimeter in the diode test position and followed the directions. I don't know what I'm doing (although I'm learning) but I'm pretty good at following directions. Psyguy mentioned I need a fully charged battery and it was charged but the voltage dropped on the battery again to 11.65, so I'm assuming that may be foiling the test. I just came back in from trying to test again via the diode test position and resistance testing and still have nothing (OL). Could my R/R be so bad that OL is all I'm going to get? My meter works fine on other items I'm checked but not with my R/R.

Anyway, I started to test my R/R because I did some other tests to figure why my battery was not charging and the stator seemed to check out okay so with the results I posted in another thread, it was suggested (by all who replied) that I should test my R/R because it may be bad.

From what I have read and was able to follow, it does sound like my R/R is bad but I still want to be able to test it and understand what I'm doing and how the electrical system runs.

ALSO, I was reading BassCliff's pictorial on replacing the R/R (I can totally do that now with all the fooling around I've done with it) and I noticed that my R/R is nothing like the Suzuki model as shown on the second page of his pictures. I had my bike in for work a couple years ago and I was wondering if they switched one out on me without me knowing.

Duaneage, sorry I messed up your spelling in a couple of my last posts.

N.E. Ohio, as in Stow, by way of Parma. Redman, when were you in Euclid? Did you know any of the Drozins? Oh, we were the Parma Redmen.

Ed

[tomm]

If you're measuring your diodes correctly and they are reading open both forward and reverse, that would be consistent with the lower voltage you're seeing, especially under load. Sounds like one or more of the rectifier diodes are blown.