R/R confusion over stator papers

[Buskyboy]

I have 1978 gs 750e and am having a charging problem. I have charged and tested the battery and it is Ok 13V. I have done the tests on the stator and all is OK each shows continuity and no leakage to the frame and each phase outputs 85 V at 5000rpm.

Now here's my problem I have tried to check the R/R and have indeed even bought another 2nd hand one but both show the same results.

I am checking the diodes for one direction continuity. The problem is that the stator papers give 2 different ways to check this .

In FAQ the way to test the wires is exactly the opposite to that in the fault finding chart. However the testing in FAQ is showing the correct results for me . i.e. full resistance in one direction and continuity in the other.
(same readings with the other R/R) The opposite to the fault finding chart.

My question is is the R/R working or not?

other Information
My bike drains the battery very slowly its is only show a charge of about 11.5 -11.8 its a real tough one.

Any thoughts

Your help would be appreciated.

Cheers Patrick.

[TheCafeKid]

Either 78 or 79 they switched to a all in one R/R... i think it was 79 and then switch back to two seperate units in 80, and from there i think they switched again to a single unit. If yours is seperate, youll have one mounted to the side of the battery box and the other mounted underneath...are you testing them both or just one?

[Buskyboy]

Thanks for the reply. I know the the regulator and rectifier were seperate on the 1978. Mine however must have been modified by a previous owner it has a combined R/R with 6 wires (3 yellow,one red, one black and one brown). It was probally done at the same time as electronic ignition was added.

Cheers Patrick

[BassCliff]

Hey howdy hey!

Mr. BuskyBoy,

Let it be known that on this day you are here by cordially and formally welcomed to the GSR Forum as a Junior Member in good standing with all the rights and privileges thereof. Further let it be known that you can improve your good standing with pictures (not you, your bike)! :-D

I'm a little confused as to one of your test results. When the bike is running, what voltage do you get at the battery? If you get only 11.5-11.8vdc at the battery terminals at around 4000rpm, and all three legs of the stator put out 80vac, and you are sure the battery is good (you had it checked?), then it must be the r/r. As Mr. CafeKid suggested, you may have a separate regulator and rectifier. If the rectifier checks out (it has diodes) like you say (infinite resistance one way, continuity the other) then it may be OK and the suspect is the regulator. I'm sorry I don't have a schematic for your bike. Do you have a manual? Nothing beats having a real manual. Have you tried http://www.repairmanualclub.com ? That site might have one to download.

I don't recall seeing a charging system troubleshooting procedure in the Old Q&A. I used the chart in the Stator Papers with success.

I have found that passive tests on the r/r with a meter may not necessarily show up any defects that occur at full voltage with full load. You could always install the "new" r/r and check the charging voltage at the battery again.

Thanks for joining us and please forgive me if I state the obvious.

Thank you for your indulgence,

BassCliff

[TheCafeKid]

It is also possible that your stator is gone south...From what ive read...and i am quite possibly wrong, when the reg goes bad you'll have an over charge and actually get too much to the battery...if your stator is not charging you can slowly drain the battery, as it takes very little to keep the bike going once its going...especially with the headlight of (you do still have that switch right?) It also may be not fully charging..im having the same problem with my alternator on my car..its charging...just at 30 amps instead of 80 like its supposed to...cant keep up with the lights on for long...but i can drive forever with the lights off.

[Buskyboy]

[CODE]I'm a little confused as to one of your test results. When the bike is running, what voltage do you get at the battery? If you get only 11.5-11.8vdc at the battery terminals at around 4000rpm, and all three legs of the stator put out 80vac, and you are sure the battery is good (you had it checked?), then it must be the r/r. As Mr. CafeKid suggested, you may have a separate regulator and rectifier. If the rectifier checks out (it has diodes) like you say (infinite resistance one way, continuity the other) then it may be OK and the suspect is the regulator. I'm sorry I don't have a schematic for your bike. Do you have a manual? Nothing beats having a real manual. Have you tried http://www.repairmanualclub.com ? That site might have one to download. [/CODE]

Thanks for the welcome. I was a member in the past so am rejoining. Its a great site and forum.


well guys i have put in the new R/R and it is a single unit for sure. Both are showing the same results. I have checked the voltage from the output (red lead form the R/R an earthing it and it is only showing 11.5 volts. I have the manual and it does show separate regulator and rectifier but it is defiantly not the same on my bike. As for the battery I have charged it with a trickle charger and it charges to 13v it seems to hold that charge.

pictures of myself are on my website www.pat-trick.com.au

cheers

[SPARKSS]

Hi there Patrick. I've owned 2 different 79's (550 and 1000) and both had a seperate regulator and rectifier unit. Your initial testing sounds ok.....you verified that the stator is an isolated AC source with sufficient output and, that you've found all 6 diodes in your rectifier bridge appearing to be normal (flow current one direction, negligible reverse). Assuming the bridge (or combination unit) is wired correctly, what MIGHT be missing is the rectifier ground connection to the bikes chassis AND if that connection is to a rubber insulated plate, a bonding wire across the rubber insulator/isolators (so that the battery negative also sees this connection!).

Without the rectifier bridge grounded AND with the stator windings properly isolated FROM ground (normal!), you don't have a complete circuit for the rectifier to work! The REGULATOR (whether a seperate unit or part of a combined unit) typically makes use of devices called ZENER diodes which shunt a peak portion of the stators waveform to ground, effecting a crude "regulation" of rectified voltage, once again, IF THE GROUND is intact for the rectifier bridge

[Steve]

I have 1978 gs 750e and am having a charging problem. I have charged and tested the battery and it is Ok 13V. I have done the tests on the stator and all is OK each shows continuity and no leakage to the frame and each phase outputs 85 V at 5000rpm. ... My question is is the R/R working or not? ... My bike drains the battery very slowly its is only show a charge of about 11.5 -11.8 its a real tough one.

According to the tests you have done (and what is possible), your R/ is working, but your /R is not. :shock:

It is rather easy to check the diodes in the rectifier, as you have done, but this is a combination Rectifier/Regulator. The regulator is not so easy to check without running it. Apparently, according to your tests, the rectifier is fine, but the regulator is shot. Also, based on the wires you mention, your bike has received a Honda unit. You can search for another on eBay and hope for the best, or contact Duaneage on this forum and get one that he as already tested and re-terminated to match your bike. Good service at a good price, too.


.

[duaneage]

I have RR's in stock, PM me if you need one. I can customize the wire lengths as well. The single Honda RR replaces the duplex suzuki system easily.

[IanFrancisco]

Thanks for the reply. I know the the regulator and rectifier were seperate on the 1978. Mine however must have been modified by a previous owner it has a combined R/R with 6 wires (3 yellow,one red, one black and one brown). It was probally done at the same time as electronic ignition was added.

Cheers Patrick

That sounds like a Honda R/R with a sensor wire that needs to be connected to a switched power source (taillights, etc.) I THINK, and I may very well be wrong, that the brown wire is the sensor wire. The sensor wire detects the voltage and varies the regulator accordingly. BassCliff just did this mod and will know for sure.

The Honda R/R's are reputed to be robust, but who knows for sure? It's cheap enough to try another one or two to see if the charging voltage is in spec.

[duaneage]

I've never seen a bad Honda RR, but a dead short might kill one. Before you replace anything check the wiring for problems like scrapped wires.

[Buskyboy]

thank you guys for your help. i got u this morning and went out and checked that i wasn't just stupid and that I definately had a combo unit, and inded i do thearea where the old regulator and seperate regulator are empty.

[CODE]Assuming the bridge (or combination unit) is wired correctly, what MIGHT be missing is the rectifier ground connection to the bikes chassis AND if that connection is to a rubber insulated plate, a bonding wire across the rubber insulator/isolators (so that the battery negative also sees this connection!).
[/CODE]

Which gives me some thoughts after sparkss posting the new unit is bolted to the plastic rear mudguard. Although the black wire from the R/R is is well grounded. I am going to reposition the R/R and bolt it directly to the chassis. It might make a difference.

As for the origin of my R/R it could indeed be from a honda . The new(2nd hand)one that i got was from a yamaha but the tests seem fine on it and it behaves in a similar manor.

I will try the move and see what happens and will let you know. If the reply seems late its just the time difference.

Cheers Patrick sunny Melbourne 35 degree C today.

[Buskyboy]

OK I was looking at the post from Sparkss and thought that a good earthing would maybe help. So I headed out to check it when i remembered another line in his post.

[CODE]Assuming the bridge (or combination unit) is wired correctly,[/CODE]

So I looked hard at it and it seemed wrong :shock:, it looked like the red wire was going to rear lights ... so I wired the black directly to the - battery and the red to the + of the battery ....Viola..charging to 14.5 volts and everything is working.

I was assuming that the previous wiring was in the correct place. Evidently the previous owner had wired it up wrong and i just assumed it was correct.

the simple things can be a pain in th a--.

Thank you guys for the help. I am learning fast

Cheers Patrick.

[Steve]

Thanks for posting your resolution to the problem. \\/

There is always the possiblity that the previous owner was color-blind and thought he had it correct. :shock:


.