Charging system puzzle

[earlfor]

This one has me scratching my head. :-)
With the stator disconnected and the bike running at 5K rpm, my stator AC output is 80+ volts on each of the 3 legs. Stator output is wired directly to the R/R. The R/R DC+ and - are connected directly to battery terminals.

The main battery ground wire to the engine is new. The fuse box is new as is the main power supply wire to it. The battery terminals are clean and the battery holds 13+ volts. There is no electrical leak/seepage on the battery when the bike is shut down.

If I start the bike and rev it to 5k rpm with the only power draw being the ignition (headlight and tail light off) the charge voltage to the battery is 13.2 volts. If I turn the headlight on low beam (55 watt), the charge rate increases to 13.9 volts. If I switch the headlight to high beam (60 watts), the charge rate increases to 14.77 volts. All charge rates are at 5k rpm. The charge rate increases by .9 volts with only a 5 watt increase in power consumption.

The stator is supplying the same AC voltage at all of the different DC charge rates. My question is: does anyone know if the R/R is multiple gated on the DC output? Until now, I did not believe it was as none of my other bikes have shown these charging characteristics. I was under the impression that the R/R output was linear to AC input and acceptance rate to the battery was controlled by electrical pressure after load was deducted from the total. Any remainder then would be absorbed as heat.

The charging system is working (apparently fine), but the thing that bothers me the most is if the headlight were to burn out, load would be lost and the system would not charge.

A solution could be as simple as installing a couple of 5 watt running lights to keep the power consumption above the gate value when the headlight is on low beam.

I've made and installed a new wiring harness. Apparently, the lowered resistance has resulted in not consuming enough power? :-)

Maybe I just have a half burned out R/R? :-)
????????????????

Earl

[duaneage]

Clearly the problem is too much new parts on such an old bike

only kidding

Actually I don't think you have a problem. There is a zener diode in the RR that shunts the output of the RR and maintains constant power output. Increasing the current draw requires the voltage to increase to maintain the same power ratio.

The RR responds to the increased load by increasing the applied voltage and allowing more of the Stator output to reach the bike's electrical system. The battery is merely a large capacitor for the charging system, it has a limited output of around 13.2 volts under the best conditions, the RR can provide up to 15.

You can check the six diodes in the RR if you want piece of mind, check them from each yellow wire through the grounds and the positive output lead then reverse the test for infinate ohms readings.

Of course I would check the RR ground wire, I redid mine ( and a friends 650L) and immediately noticed a difference. i am not convinced the suzuki has a bad RR design, I think the big problem is the grounding. THey tied grounds together and then strap them to the dumbest things like battery box mounts. I ran individual grounds for the RR, the solenoid, and the lights. Everybody got their own solid connection to the fram and then ONE connection from the frame to the battery.

Bonding grounds or chaining them together is a bad idea.

[SqDancerLynn1]

Are you running the third leg of the stator thru the light switch ?

[Anonymous]

puzzle

adding a frame ground really helped my system, but with every thing to the battery it should not be a problem, may be you have a ground problem in the harness that you made, going to the lights, do they get alot brighter with engine speed? since it doesn't make any since, this reply should be right in the same ball park, if the headlite goes you still have the tail lite for draw, if you put afull load on the chargeing system, at 5K and turn on a signal do you get a large change or fluctuation in voltage, ( needle swinging) on meter

[earlfor]

No Lynn, my stator has all three phases wired directly to the R/R. My headlight is rewired with its own dedicated circuit. and no longer is powered through the main wiring harness.

Earl

Are you running the third leg of the stator thru the light switch ?

[earlfor]

Re: puzzle

The headlight, tail light and turn signals have been removed from the stock wiring harness. They each have their own wiring. Each also has its own ground which is not common to the others. The headlight momentarily brightens when rpm is increased, then returns to the original brightness.
I havent meter checked the voltage in the turn signal circuit when the signals are flashing. I would expect to see the needle move in unison with the flasher tripping and the needle to return to original level between blashes. Its easy enough to check to see if anything is out of wack. :-)

I think I will recheck all the grounds. Everything seems to be working, but something in the back of my mind keeps nagging me. :-) It just doesnt feel right. :-)

Earl

adding a frame ground really helped my system, but with every thing to the battery it should not be a problem, may be you have a ground problem in the harness that you made, going to the lights, do they get alot brighter with engine speed? since it doesn't make any since, this reply should be right in the same ball park, if the headlite goes you still have the tail lite for draw, if you put afull load on the chargeing system, at 5K and turn on a signal do you get a large change or fluctuation in voltage, ( needle swinging) on meter

[DMPLATT]

I'm no expert here, as well all know. But in my factory manual, it describes the charging system in just that way. I'll read it again when I get home, but it does describe charging more or less as it is needed.



Sounds like you've got her licked Earl.

[Anonymous]

say what

Ok so the headlite does brighten when reved as well it should but does it go back to its normal brightness while still reved, or after you return to idle witch would be normal. if it does it while it is still reved then you have a R/R problem, if you check the signal draw it should have a small amount but not huge, honda RR would do this the lite would change bright to dim while at about 3K witch was an indication that it was going bye-bye.

[AOD]

The main battery ground wire to the engine is new. The fuse box is new as is the main power supply wire to it. The battery terminals are clean and the battery holds 13+ volts.

Who would use such a crazy wiring system? 8O

...oh wait...

[earlfor]

Re: say what

If the rpm's are up, the headlight brightness doesnt change. With the battery being maintained at around 12.9-13 volts, there isnt a big difference at any rpm.
It gets a little brighter on high beam when rev'd and stays slighly brighter if the rev's are up. The R/R output is stable after 5K rpm at 14.8....give or take a couple hundredths. Its the drop in charging voltage to around 13.9 on low beam that has me puzzled. High and low beam use a common ground, so it cant tbe a ground problem on the light. I guess it could be an internal element connection on the bulb itself. ?

Earl

Ok so the headlite does brighten when reved as well it should but does it go back to its normal brightness while still reved, or after you return to idle witch would be normal. if it does it while it is still reved then you have a R/R problem, if you check the signal draw it should have a small amount but not huge, honda RR would do this the lite would change bright to dim while at about 3K witch was an indication that it was going bye-bye.

[Anonymous]

what

I got it so it seems like it isn't responding to elec. pressure but like you say may be multi gated r/r, since I dont know what year it is was it orginally equiped with a seperate rectifer, regulator

[focus frenzy]

sorry for the delay in responding Earl.
your regulator is dying a slow painful death.
at above 3000-3500 it should hold a steady voltage regardless of load up to the stators ability to produce power.

with a very low load it is over compensating and shunting to much to ground.
as load is added it backs off and lets the voltage rise.
chances are if you slowly reved the engine up to red line the voltage would rise up to a point then suddenly drop as the regulator suddenly tried to compensate for the voltage being to high.
mine would steadily build voltage to over 15.5, then suddenly at around 7K rpm shunt all power to ground and drop voltage below 12!!!!

I put a new electrex on it and the voltage is dead stable at 14.5 volts from about 2500rpm all the way up and changes in the lights brakes and horn have no effect on voltage.

[bwringer]

Exactly what I was thinking, focus!

Even though the old regulator/rectifiers don't put out lab-quality power or anything, they will maintain voltage pretty closely when they're working right.

To overanthropomorphize a bit, there's a dead or dying diode in there and the others are struggling to compensate. Poor lil' fellers. Give 'em a decent burial and limber up the Visa card. (And don't ride it until you fix it, in case it craps out all the way and fries your stator.)

You've laid all the other wiring groundwork for the new part to have a long and productive life.

Or haunt eBay for a Honda reg/rect. I nabbed one from a CM400 a while back for about $12 including shipping.

Once in a great while, you see the same general thing (weird, "stepped" variations in voltage) in car alternators when the internal reg/rect starts to go blooey but doesn't poop out all the way.

[earlfor]

Ahhhh Haaaa, now that makes sense to me. :-) My first thought was a dying R/R, but then it charges normal on high load and I was puzzled why decreasing load would me it drop that much voltage. THANK YOU! :-)

Earl
P.S. Anyone want a good deal on a slightly used fried R/R....I'm willing to haggle here. :-) :-)

Earl

with a very low load it is over compensating and shunting to much to ground.
as load is added it backs off and lets the voltage rise.
chances are if you slowly reved the engine up to red line the voltage would rise up to a point then suddenly drop as the regulator suddenly tried to compensate for the voltage being to high.
mine would steadily build voltage to over 15.5, then suddenly at around 7K rpm shunt all power to ground and drop voltage below 12!!!!

I put a new electrex on it and the voltage is dead stable at 14.5 volts from about 2500rpm all the way up and changes in the lights brakes and horn have no effect on voltage.

[bwringer]

Why looky here -- a ravishing regulator rectifier from a Honda CM400:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4538257249&category=34284

Only $6 when I posted it. It's hard to see in the goofy picture, but the R/R is bolted to this big useless bracket thingy. No matter.

And yes, this unit from a little bitty 400 has plenty of capacity to handle anything the charging system on your big bad 'ol GS can dish out. Think about it -- the size of the bike has very little, if anything, to do with how much electricity it needs or generates.

And it should bolt right on to most GSs. You'll have to connect the wires yourself, but that should be a piece of cake for you, earl.

I have one of these R/Rs sitting in my garage right now, waiting to be transplanted into my GS in time of need. Actually, I have two, but one is still doing a great job attached to my wife's Honda CM400T.

These Honda regulators were made for Honda by Shindigen, and are very high quality, far more reliable than the Suzuki parts.