Charging system

[Blueknyt]

Ok, her goes, You have 3 wires coming off the stator leftside engine cover, this supplies AC current to the Regulator/rectifier unit to change the current to DC and lower it to a 13-15v output. now, i need some help with process and numbers,  the 3 wires i think are Y w/g w/b these get checked engine not running to see if there is a short to ground, or open circut, if all is well, the resistance/cont should be real close to eachother yes?    Now, with engine running and Meter set to AC and checking from wire to wire 4k rpm or so should be reading about 60 volts from any 2 of the 3 when cross checked, ok, now. how do i check the rec/reg?


i notice my light brightens alittle just off idle(normal) but once past 3-4k it dims out again. i cant keep the test leads on batt while reving,(i need aligator clips) and what ever current is coming out of stator deff will light your open for business sign for you,  yeah ask me how i know.

[Blueknyt]

bump......

[Kerry]

how do i check the rec/reg?

Here's the scoop from the Haynes manual:

Regulator/rectifier unit - check and replacement[/list:u]EDIT: 1) Changed link from sisna.com to bbburma.net ... 2) indented the link

[Blueknyt]

thank you kerry. does the book say anything about the values from testing the stator?

[Kerry]

From page 8-23:

34 Alternator stator coils - check

1 Remove the left-hand side panel.

2 Trace the alternator wiring back from the top of the engine sprocket cover and disconnect it at the connectors.

3 Using an ohmmeter or continuity test light, check for continuity between each of the wires on the alternator side of the connector, taking a total of three readings, then check for continuity between each terminal and earth (ground).  If the stator coil windings are in good condition there should be continuity (zero resistance) between each of the terminals, and no continuity (infinite resistance) between any of the terminals and earth (ground).  If not, the alternator stator coil is at fault and should be replaced.  Note: Before condemning the stator coils, check  [that] the fault is not due to damaged wiring between the connectors and coils.[/list:u]EDIT: Changed formatting but not content

[Kerry]

As backup / followup to your original post, here are some more scans from the Haynes manual:

Charging System - 1
Charging System - 2

EDIT: Changed links from sisna.com to bbburma.net

[Blueknyt]

AH YES, CAPTURED AND PRINTED, Bless you kerry, i think i might have found the problem  the connection for w/g is abit corroded, checked a few othre forums and found a common thing, the stator wires often get hot and either melt the plugs(where applied) or water collects and corrodes the connections.  most of them recomend cuting and soldering the connections to ensure good connections. i might do this, or i might just go find a 3 wired plug.

[Rema1000]

I've had to jump my GS the last few cold mornings.  I looked at the battery last night, and it was low on water.  Voltage was 12.75 with no load, but dropped quickly when I turned-on headlights.  Each cell needed 5cc to get up to the min-fill line, and another 15cc to get up to the max-fill line.  I last filled it about 6 weeks ago.  

I charged it for 4 hours last night.  This morning (32 deg. F), it read only 10 volts .  I charged it again for an hour, so I could start the bike and ride to the battery store (charging voltage got up to about 14 at the end).  However, when I started the bike, the idle voltage jumped up to 15v!  I've read reports of idle voltage at 13, and 14.5 or 15 at 4k-5k RPM, so I thought "A-Ha!  bad regulator, maybe its 20v at 4k rpm".

After letting the bike warm-up, I checked voltage at idle, 3k, 4k, 5k and 6k RPM: all read 13 volts.  The voltage had dropped from 15 as the bike warmed-up (?!).

So now I'm not sure: battery is OK, just low on water; battery is dying; or bad regulator.  How often do you need to add water to yours (Srinath, don't rub it in, I know yours is sealed!)?

[Rema1000]

I got a digital meter, and found that the GS was charging the (very flat) battery at 17.5 volts after startup.  Then, after about 2 minutes, the voltage just dropped suddenly to 14.4 (where it should be).  After a ride, the bike was still charging at 14.4.  I don't see any variation in voltage when I run the engine at 2k, 4k or 6k RPM.

Can anyone confirm that the voltage immediately after startup is out of spec (max. 15.5v), or is it just me?

[Blueknyt]

its weird, swaped rectifiersaround,  lights are bright at 15- 4k, once above that they dim out. i dont know what the hell is going on, but its driving me nuts.

[John Bates]

I got a digital meter, and found that the GS was charging the (very flat) battery at 17.5 volts after startup.  Then, after about 2 minutes, the voltage just dropped suddenly to 14.4 (where it should be).  After a ride, the bike was still charging at 14.4.  I don't see any variation in voltage when I run the engine at 2k, 4k or 6k RPM.

Can anyone confirm that the voltage immediately after startup is out of spec (max. 15.5v), or is it just me?

Yes, I noticed the same thing.  Apparently, at startup, the regulator senses a very low voltage and puts out max power.  It takes a while for the system to stabilize to normal values.

[ubul]

Hi all. This is my first post here.
I have the classic charging system problem on my newly acquired 1990 black GS500E. My conclusion of the test is that, one of the three wires out of my alternator could be loose. I did the AC voltage test at running engine, and one wire seems to be open circiut. No voltage, no resistance, nothing at all.
My question is, how do I check if it's the coil broken or only the wire disconnected? Is it recommended to take it apart at home? Shall I drain the oil or take the block apart to reach the stator or the alternator or whatever that wire connects to?

Since I live outside the US, I can't get the service manual book easily. I would appreciate any help, scans maybe, how to address this problem.

[starwalt]

Hi all....My question is, how do I check if it's the coil broken or only the wire disconnected?...

Hello and welcome! It sounds as though you have a VOM or multimeter of some type. Please confirm this.

If you can check resistance (ohms), you have two possible places for a bad connection. The three bullet connectors between the winding and the harness OR the connector between the harness and the RR.

Here is a photo of a naked harness with the RR and stator connected. Check the green circled connections after you find them on the bike.


You can use the bullet connections to test the winding resistance wire to wire for all three pair. They should read almost zero ohms for each pair. If not, check the wiring up to the case for a break or cut. If good, then check back to the RR, again zero ohm per wire bullet to plastic connector.

That will check the windings! Let us know your luck.  

[The Buddha]

Hi all. This is my first post here.
I have the classic charging system problem on my newly acquired 1990 black GS500E. My conclusion of the test is that, one of the three wires out of my alternator could be loose. I did the AC voltage test at running engine, and one wire seems to be open circiut. No voltage, no resistance, nothing at all.
My question is, how do I check if it's the coil broken or only the wire disconnected? Is it recommended to take it apart at home? Shall I drain the oil or take the block apart to reach the stator or the alternator or whatever that wire connects to?

Since I live outside the US, I can't get the service manual book easily. I would appreciate any help, scans maybe, how to address this problem.

OK My first guess ... Someone opened the sproket case and forgot to clip the wire back in the clip that holds the 3 pack of wires out reach of the chain/sproket ... dont ask how I know ...  :x  Usually happens when you toss the airbox in favor of K&N's also ... extra slack in wires needs to be pulled out and tied off ... else asking for trouble.
Cool.
Srinath.

[ubul]

Thanks for the info. The RR is good, I measured at the bullet connectors, and I measured infinite resistance and no AC voltage when revving. That is why it's possible the cable is cut inside the sprocket case. I will take it apart, lay the bike on its side, take off the sprocket cover and the left side cover. I will measure the connections between the stator and the bullet connectors. If the wire is bad, then I will know it's not the stator at fault.
If the stator is bad, I will take it to the electronics guy and he will fix it for me. I'm not in the mood of buying another stator.
Laying the bike on its side is like taking it to a hospital for an operation. Gives me a strange feeling.

Oh, one more question:
What do I do with the clutch cable if I take the sprocket cover off? Can it just stay connected hanging around?

[Kerry]

What do I do with the clutch cable if I take the sprocket cover off? Can it just stay connected hanging around?

Yep.  In fact, it's better to do it that way.

To remove the clutch cable entirely you need to bend a metal tab to release the "ball" on the lower end of the cable.  It would be a good thing to not bend that tab any more times than you need to.  Once per clutch cable replacement is plenty!

[ubul]

Yaay! I fixed it. My charge is back to normal now.
The wire inside the sprocket case was cut, but everything was in place.
http://web.axelero.hu/icram619/kepek/gs500/stator.jpg
Soldered it back together, should be good for a while.
http://web.axelero.hu/icram619/kepek/gs500/left_open.jpg
http://web.axelero.hu/icram619/kepek/gs500/bike_side.jpg
As I took it apart, it seems that my clutch push rod in picture 2 is broken in 2 pieces, but it works fine that way, too.

[starwalt]

Hurray!  

Your method of accessing the bottom of the bike by laying it down is a little unorthodox, but it got the job done.  

Again, congratulations! Take some pictures of Hungary and your GS for us and post them. Ride Safe!  

[Bluebellylint]

how do i check the rec/reg?

Here's the scoop from the Haynes manual:

Regulator/rectifier unit - check and replacement[/list:u]EDIT: 1) Changed link from sisna.com to bbburma.net ... 2) indented the link

I did the Check Kerry linked to above and came out with ~5.5 M ohms between Y1, Y2, Y3 and. then I got 9.78 between R and B/W. are those common failure values? I would think the resistance would go down rather than up if the RR is faulty.
P.S. I made sure my multimeter was working correctly by testing some resisters of known value afterwords and it passed.

[Mountaineer]

One way to cut corrosion of the connectors is to liberally use dielectric grease which keeps out water and air. Buy it at any auto parts store.