Electrical Problem(s)

[Anonymous]

I have an '81 GS850L with about 12,000 miles on her. My battery is not getting charged. I now have a new, freshly charged battery. She reads 12.75vdc when not running and drops to 11.83vdc while running. This number increases very slightly when I rev the engine, never to exceed 12.0 volts. I used the stator papers flow chart to diagnose the problem and was only able to get to the second test, before becoming confused. When I connect the black lead of my multimeter to the battery(+) and the red multimeter lead to the RED output wire of the RR, the multitmeter reads -0.2v. My leads are connected correctly into the multimeter. I am confused as to why I would get a negative reading? Also, I noticed one of the connectors for one of the yellow wires (actually white with a red stripe) showed signs of being burnt. When the bike idles and I have the low headlight beam on, she flickers a bit. As I rev up the engine...the light goes dim just under 2000 rpm. Above that (rpm) it is good and bright. The high beam appears to work normally, no flickering, no dimming. Should I just go ahead and replace the RR? Any help is greatly appreciated! Thanks in advance!

[rustybronco]

Let me see if i can help...
your battery is DISCHARGING, which means the battery voltage is higher than the output voltage of the stator, so the current flow will be backwards of a charging system that works properly so it should be a negative (-) voltage shown. Please correct me if i'm wrong...
I would finish the rest of the tests first and then post the results for confirmation. that burnt wire doesn't sound like to much JOY! Remember the stator pages just say .02 volt not positive or negative IMO.

[Anonymous]

So if my reading lands right on the money, 0.2v (and I ignore that it is a negative .2)....Should I consider it less than .2 or more than .2? Thanks again.

[rustybronco]

you can't ignore the negative or positive sign i just tells you which way the current is flowing on the wire you are measuring in relation to a reference point, (in this case it is the battery voltage) it still exists! what you are measuring is the voltage drop on the wire and that is .02v....

question #2 is .02v exactly... not above or below, I would think anything .02v or below is acceptable. though i'm not an engineer.
I hope this helps... Dale

[focus frenzy]

first get rid of those burnt connectors from the stator to the regulator.
did you test the stator output?
if it was in spec then the regulator is bad.
the stator pages do not test the regulator but test the diodes of the rectifier.

if you have over 60 volts from all three stator wires(measuree from wire 1to 2, 2 to 3, and 3 to 1) (at 5K rpm) and no continuity from the stator wires to the engine case the stator is good.
relocate the regulator ground to the battery ground. and run a jumper wire from the regulator output (red wire) to the battery positive terminal and check running voltage at the battery.
if you still are not charging the regulator rectifier is bad.

the rectifier test is pretty much a waste of time, as a bad rectifier will suck the battery dead when the engine is off or blow the main fuse.
so if the fuses dont blow and the battery doesnt go dead over night, the rectifier is ok.

also rectifier going out shows up as the lights flickering at idle. (bing!!)

[Anonymous]

Okay....cool. Thanks for the help. I will be testing again tonight, starting with the stator. It sounds like you are leaning towards my RR being bad. One thing though, you say if the rectifier is bad it will drain the battery...and the flickering lights at idle points to a bad rectifier. I have the flickering, but the battery does not get drained over night. Would this be because the rectifier is just starting to go? I'll post my findings tomorrow morning.... Thanks again for the help and forgive me for being slow. My whole world gets out of wack when I can't ride...

[earlfor]

Re: Electrical Problem(s)

OK, something is broke. :-) The charging system is comprised of the stator, regulator/rectifier, and the battery. The stator outputs AC voltage.
The R/R rectifies that to 12-14.8 volts DC to charge the battery. The bike runs on DC voltage, so in essence, it runs completely off the battery always. You have a burned connector on one leg of the stator that connects to a AC input yellow wire on your R/R. It is likely that the R/R on that phase of conversion of AC to DC is faulty and shunting to ground. The wire would consequently be burned. The question is has the added resistance and heat causing the burning been enough to destroy one leg of the stator. I expect your R/R is faulty, but that may not be all of the problem. The only way I know to positively fix this is to check every part of the system.

The first thing you must have is a good, charged battery. A charging system cannot work if it has no place to put a charge. Remove the battery from the bike and put it on a charger (fill to the line for electrolyte level with water.........never add more acid) Charge at 2 amps until the voltage in the battery measures at least 13 volts. Sit the battery aside for 8 to 12 hours and recheck voltage. If voltage has dropped below 12.8, you need a new battery.

Once the battery is OK (new or holding a charge) you can check the stator. (if you have installed a new battery, charge it to a minimum of 13 volts before installing it in the bike. A new battery will take about 8 hours at a 2 amp rate on an automatic charger. Prior to that time, a meter will show a surface charge and not be indicative of actual deep charge.

Install the charged battery. Check and clean both ends of the negative ground cable on the battery. One end is on the battery neg terminal, the other end connects to a bolt on top of the transmission. Temove that bolt and clean the ring connector.

Set your multimeter to the AC scale 200 (AC scale) There are three yellow wires coming from your stator and ending in a plug. Disconnect that plug. The test is done with the plug disconnected. AC voltage has no polarity, so it will not matter which color meter lead you place on which wire of the three yellow. If we number the wires 1,2, and 3, the you want to place the meter leads on 1 and 2 for one phase, on 1 and 3 for the 2nd phase and on 2 and 3 for the third phase of the stator. Each phase should show 80 volts at an engine rpm of 5000. Anything over about 65 volts should be enough to keep the battery charged. All phases should read close to the same value. Start the bike, run it to 5k rpm and check voltages on the pairs of wires I stated. Do NOT let the bare ends of the three yellow wires touch/ ground to anything and not to each other.

Assuming your stator checks within values above, plug the stator back into the R/R. On your R/R, there is a black wire and a red wire. The black is 12v DC negative output and should be connected to your battery negative terminal. If it is not now wired that way, change it. The red R/R wire is 12v DC positive output and should be wired directly to the battery positive terminal.
If it is not, change it so it is. Any other wires the red may have been connected to will now be capped off/taped off and no longer used.


Set your multimeter to the DC20 volt scale. Connect the meter to the battery terminals. (red +, black -) Start the bike and run it to 5k rpm.
voltage at the terminals should be between 14 and 14.8 volts. Probably will be about 14.5 or so. If voltage is within this range, the R/R is fine.

Each step above must be correct before you can proceed to the next.

I would not run the bike with the R/R connected to the stator until the problem has been determined as doing so may toast the stator (assuming it is not already toasted)

Lemme know what you get. If I miss getting back, pm me if you wish.

Earl

I have an '81 GS850L with about 12,000 miles on her. My battery is not getting charged. I now have a new, freshly charged battery. She reads 12.75vdc when not running and drops to 11.83vdc while running. This number increases very slightly when I rev the engine, never to exceed 12.0 volts. I used the stator papers flow chart to diagnose the problem and was only able to get to the second test, before becoming confused. When I connect the black lead of my multimeter to the battery(+) and the red multimeter lead to the RED output wire of the RR, the multitmeter reads -0.2v. My leads are connected correctly into the multimeter. I am confused as to why I would get a negative reading? Also, I noticed one of the connectors for one of the yellow wires (actually white with a red stripe) showed signs of being burnt. When the bike idles and I have the low headlight beam on, she flickers a bit. As I rev up the engine...the light goes dim just under 2000 rpm. Above that (rpm) it is good and bright. The high beam appears to work normally, no flickering, no dimming. Should I just go ahead and replace the RR? Any help is greatly appreciated! Thanks in advance!

[rustybronco]

Sorry should have typed .2v

[Anonymous]

8O Okay...so I've consumed a few beers while testing out my stator and RR. I'm in the zone. I'm thinking my stator and RR is bad. Maybe you can confirm. I've cleaned up the GND connection from the batter terminal (cleaned it) to where she bolts on the tranny (cleaned it). Keep in mind I'm using a brand new battery. This is what I've found: 3 wires on the stator, engine revved to 5000rpm (also checked resistance afterwards) , Between 1-2 = 26VAC, (0.9 ohms with the engine off and stator disconnected). 1-3 = 26VAC, (0.8 ohms w/eng off & st dis). 2-3 = 19VAC, (0.9 ohms).

Now I know I shouldn't judge the RR using a bad stator, but this is what I found with the stator disconnected (so the bad stator has no impact on these tests): Beginng of test phase C. Diode test w/ RED multimeter lead to the RED + output wire of the RR. BLK multimeter lead to one of the yellow wires on the RR = ABSOLUTELY NOTHING. I don't know what this means. It was this way for all of the YEL wires. When I reverse this (which is the next procedure) and put the BLK mm lead to the RED + ouput wire and the RED mm lead to the YEL wires I get 0.502, 0.484, and 0.497 1,2,3 respectively. Which for that test would be acceptable. So why didn't it work the other way around? Did the bad stator fry the RR? Right now I'm looking for a new stator and RR. Gonna go with electrex... Any other tests I should be doing? Thanks for all so far!

[earlfor]

Well, that conclusively shows you have a burned out stator. No doubt whatsoever. Replacement time.

Earl

[quote="chester"]8O Okay...so I've consumed a few beers while testing out my stator and RR. I'm in the zone. I'm thinking my stator and RR is bad. Maybe you can confirm. I've cleaned up the GND connection from the batter terminal (cleaned it) to where she bolts on the tranny (cleaned it). Keep in mind I'm using a brand new battery. This is what I've found: 3 wires on the stator, engine revved to 5000rpm (also checked resistance afterwards) , Between 1-2 = 26VAC, (0.9 ohms with the engine off and stator disconnected). 1-3 = 26VAC, (0.8 ohms w/eng off & st dis). 2-3 = 19VAC, (0.9 ohms).

[Anonymous]

Should I buy a RR right away or wait and check 'er again after I put the new stator in?

[earlfor]

Doing a static test for resistances, the stator condition is not a consideration. However, I dont trust resistance tests. I rely on engine running (dynamic) testing. For an engine running test, the stator must be functioning properly. (cant check voltage that isnt being produced in the first place :-) )

It is rare that a stator will burn out first. If the stator burns out, there is no output to the R/R. If there is no output to the R/R, there is no reason for it to burn out as it is not being used ...so to speak. Its the R/R that shorts and destroys the stator usually. Your burned yellow wire is evidence of that. I would go ahead and order a R/R when I ordered a new stator. I think the possibility of your old R/R being servicable/working properly is zero.

Order a new stator cover gasket too, You'll probably need it. And.........:-) heh heh do not try to pry the stator cover off or insert anything between the cover and mating surface. Also, the stator is oil cooled, so you will need to either drain the crankcase oil, or lean the bike to the right abour 40 deg on something before removing the cover.



Earl

Now I know I shouldn't judge the RR using a bad stator, but this is what I found with the stator disconnected (so the bad stator has no impact on these tests): Beginng of test phase C. Diode test w/ RED multimeter lead to the RED + output wire of the RR. BLK multimeter lead to one of the yellow wires on the RR = ABSOLUTELY NOTHING. I don't know what this means. It was this way for all of the YEL wires. When I reverse this (which is the next procedure) and put the BLK mm lead to the RED + ouput wire and the RED mm lead to the YEL wires I get 0.502, 0.484, and 0.497 1,2,3 respectively. Which for that test would be acceptable. So why didn't it work the other way around? Did the bad stator fry the RR? Right now I'm looking for a new stator and RR. Gonna go with electrex... Any other tests I should be doing? Thanks for all so far!

[Anonymous]

That bites... So...once I replace these, will the new ones blow too? Is there anything else I need to correct to cure the problem...or is this the cure? Thanks a mil.

[Anonymous]

Since I've had my share of electrical problems myself I have to read these posts as they come up.
I replaced the stator a few weeks ago. I broke the gasket and had to wait a week for a new one. Before you order the gasket, stator and RR you might want to consider taking the cover off the stator first. I fried a couple of screws getting them off and the wait was a week for those too at the Suzuki dealer. They are not all the same size so ordering one or two for under a buck each might not be good enough. I think I had three different sizes. So for another 8 bucks or so (since you're talking about spending over $200 for a new RR and stator) it might be worth your while to get the screws too. If you have trouble figuring out which screw goes in which hole you can make a little drawing when you take them out or go to bikebandit.com and look at the drawing there.
Good luck getting the cover off. Earl is right. You don't want to pry it off with anything other than your fingers. I used a rubber mallet to bang it out some to get my fingers behind the cover, then I PULLED. Another piece of advice, use locktight of some sort for the small screws inside with the stator. You don't want to have those puppies come loose later on down the road.

[earlfor]

My observation is that 95% of charging system faults will never occur if a good battery is kept in the bike and the electrical connections in the charging system are kept clean. Also, the way the charging system is configured, you must always run the headlight and preferably on high beam. New owners it seems mistakenly think that conserving energy (not running the headlight) will decrease the load on the electrical components. The opposite is true. Ideally, you want to use everything that is being produced with just enough left over to maintain the battery. If nothing is produced in excess of what is required by the bike to function, then nothing will need to be shunted to ground and resistance and heat will be minimal. In the end, it is heat that is killing the charging system, not use.

So, following the above should solve your problem. After installation of the new components, do a voltage check of the stator and R/R as you have already with the old to verify that both are working properly. Just because something is new, does not guarantee it is in working order. :-)
Sometimes, they screw up. LOL

Earl

That bites... So...once I replace these, will the new ones blow too? Is there anything else I need to correct to cure the problem...or is this the cure? Thanks a mil.