1981 Suzuki GS850G Electrical Problem

[Jcarlson]

Ok folks, I've posted this problem before but I'm getting tired of chasing my tail with this bike. Four summers ago I replaced the stator & R/R with new aftermarket ones. The bike ran great all summer long. The next summer it ran great until about October that year (2009). I stopped at a gas station, shut it off then it would not start. Recharging/jumping the battery will make it start again but shut it off after 20 minutes or so of riding and I'm dead. Thinking possibly a bad battery I replaced a two year old YUASA with a Bikemaster gel battery. Same story. Bottom line is it would not recharge the battery while riding.

I've checked every ground there is and they all seem good and I've been through all the stator & R/R tests there is according to Clymers. I don't remember the numbers cuz I did it last year but they were'nt bad. Last year while doing a load test on the R/R I pulled the male plug off red wire.

I picked up a used R/R from eBay and replaced it today (it supposedly came off a running bike, but you never know for sure with eBay). I charged the battery today as well. Turn the key, lights come on but starter barely cranks. It still won't start.

With the key off I checked the battery - 12.36V. Turn the key and it drops to 11.96 +/-, and that is without hitting the starter button.

Is there a way to hook the bike to something and let it do its thing and find what the problem is? You know how the auto parts stores have that machine where they can test the battery, alternater, voltage regulator, etc to find whats gone bad? Is there one of those for bikes? Is there a broken wire somewhere? A bad component somewhere? I've been all through this thing, but I'm no bike mechanic. I can rebuild a motor and make it run, but I am NOT electrical savvoy.

I'm at wits end with this thing and don't know where else to turn. Anything you have to offer will be great and if anyone would like to swing by and have look you're most welcome to do so. I'll take anything I can get at this point.

Thanks in advance!

Jim

Edited April 14, 2012 by Jcarlson

[Strictly Street]

Sounds like a short in the wiring.

Had a similar problem once and fixed it by taking out all the fuses and measuring the batt volts. Then replacing the fuses one at a time to see which circuit had the short. then tracing out the wires to find the one with the insulation worn off from rubbing against the bottom of the seat. Applied tape and it was fixed.

It takes awhile but there aren't that many wires on a bike. Patients is the best tool for this job.

[mello dude]

- You kinda need to start over --- pull the battery after an overnite charge and go to autozone or batterys plus and get it load tested. The first point is the charging system is worthless without a good battery. Decide good/bad and go from there.

If it wont turn over with a known good battery, you may have starter motor type issues. - I might just say effe it and do a car battery jump. If you get it running ==

Go through this starting point list.

Steps:

- With good battery fire it up. Run at fast idle for a couple minutes.

These are R/R quick checks--- do first..

--- With voltmeter at battery get voltages -- idle volts? 5000 rpm volts? Whats the nunbers? Should be in 13ish min idle and in 14s at revs.

- Check stator

- 1. pull connector apart. Set meter to resistance. Check pin to pin, 3 yellow wires, A to B, B to C, C to A. Whats the numbers? Should be less than 1.0 ohms.

- 2. Check continuity from each A,B,C pin to ground, -- -should be infinity - nada nothing. no continuity.

- 3. Crank it back up. Do another pin to pin thing, but set meter on AC volts. idle and 5000 rpms. What's da numbers? Should start 15ish and climb 50ish and more. -- Do again with the bike hot.

For even more detail on it heres a chart from electrosport.

http://www.electrosport.com/media/pdf/fault-finding-diagram.pdf

As far as components for your ride, I wouldnt buy something off ebay unless you know what it is. "Bike was running" could mean anything. - I would jump for an updated MOSFET part or a "series" type R/R.

Grab a MOSFET from here:

www.roadstercycle.com

or series type from

http://www.chrome-addiction.com/g-compu-fire-40a-3-phase-charging-systems-46974.php

Compu-fire series # 55402 – last part on the list

-- After heavy research I'm running the Compufire part. - It was designed to be a Harley part, but a lot of Triumph, Aprilia and Honda VFR guys are using it for a conversion. There is even a guy with an old GS1100 that is using it. (Yeah, it was funky to put a Harley part on my VFR, but screw it, I'm done. I have a slam dunk perma fix for the charging system now on the viffer.)

-Series R/R have an advantange over a MOSFET part in that it only switches "on" when voltage is needed vs other is "on" full time and dumps excess voltage as heat. - Sort of just enough throttle on vs full time throttle and brakes on to control speed. - Other benefits is the stator lasts longer because its not "on" full time, and then because of the this, the bike runs cooler too.

If you get where you need a stator get it rewound here

http://www.customrewind.com/

Good luck

Edited May 1, 2012 by mello dude

[mello dude]

Sounds like a short in the wiring.

Had a similar problem once and fixed it by taking out all the fuses and measuring the batt volts. Then replacing the fuses one at a time to see which circuit had the short. then tracing out the wires to find the one with the insulation worn off from rubbing against the bottom of the seat. Applied tape and it was fixed.

It takes awhile but there aren't that many wires on a bike. Patients is the best tool for this job.

Agree with this - backtrack the basics first....

[Al Z. Heimer]

http://www.youtube.com/watch?v=XhRPLgH6uZg What you need to do is perform a voltage drop test to test your starting circuit. Like the video says,you have to start with a known good battery.Just remember----the test alone at pos. term. on battery involves 4 tests----lug on battery for base voltage,fastener,eyelet on cable and cable itself. do this at every connection. When finished,do the same test on the neg. side. hope this helps. http://www.youtube.com/watch?v=yV5wdGtP34o Some good info on this vid also.

[Gixxus Christ!]

I know you said you checked your grounds but check them again, pull the bolts out that connect main grounds to frame and check for corrosion. Set volts/ohms meter for continuity and check between negative terminal and frame.

[Jcarlson]

I'm still here guys. I haven't given up, I just haven't wrenched it since Sunday. I did what Strictly Street suggested and it's on the 15A line, which basically is the whole bike. Once I found that line runs to the ignition I said "Ohhhh Fuuuuuuudggggge" like Ralphie in "A Christmas Story".

Here's what I've found - the fuse block is grounded to the battery box, the start relay is grounded somewhere in the wiring harness, the battery box is grounded to the chasis, "I hear the word of the Lord!!"

I'm slowly working my way through the wires cleaning, sanding, replacing if needed every nut, bolt, screw, eyelet, connector, you name it. I checked voltage and continuity on the starter & relay and that's all good, but that's as far as I got.

I won't get to it again until next monday so I'll keep my fingers crossed and keep chugging away. Thanks for all the tips and I'll do what everyone has suggested so far, it's just take some time.

Jim

[Jcarlson]

I GOT IT!!!! I'm not sure what I did but it fired right up!! I finally got back to it today. Not knowing where to start I figured I'd just pick a ground and check it out.

I started with the turn signal switch. I took it off and it looked pretty clean but I hit it with some emery cloth anyway, cleaned the handlebar, and put it back on. Then I removed the starter disconnect switch from the clutch handle. It never worked anyway but I cleaned it too. Then just for poops and hooha's I swapped out the self cancelling turn signal controller with one I had from an old wiring harness I bought last year.

I turned the key and it freakin fired right up!! I'm not sure what I did but it worked - probably the turn signal cancelling box but who knows and who cares. It even recharges the battery now too. The bike is 31 years old but it runs like brand new. Now I just need to clean it up from winter storage and hit the road!!

I want to say thanks to all the guys who chimed in on this thread to lend a helping hand. That's what this place is all about.

Jim Carlson

[Jcarlson]

I spoke too soon. In the time it took to write my last post the battery was drained to 12.2V - not enough to start it again.

When it was running earlier it ran like a champ. Before I started it I checked the voltage -12.6V. I ran it about 10 minutes and shut it down. I checked voltage and it was 13.1V. That's good! It recharged. I hit the starter again and it fired up again. I shut it down and came in to post my wonderful news. 15 minutes later it was drained to 12.2V.

Something somewhere is draining juice when the iginition is off. Anybody have any clues or do I just keep doing what I'm doing?

One more thing. As I'm trying to start it the battery wears down while it's cranking over. It wears down to a point to where it won't turn the starter anymore. And it doesn't take long to kill it either. Would the starter be the problem - drawing too much juice?

[mello dude]

Please do an overnite charge on the battery, and then take it to get a load test. You need to confirm good/bad. How old is the battery?

- You're spinning your wheels untill your know you have a good battery. After that - go to post #3.

[max power]

I'm with the others here. Check/clean every wire connection. It it probably grounded somewhere. A lot of the old bikes (hell, even some of the newer ones) had soldered wiring in the harness that over time corrodes or insulation that wears from vibrations and grounds out to the frame or other metal components. Trace every wire out and you will eventually find it.

Good luck.

[Jcarlson]

Mello Dude - I bought the battery two year ago (October of 2010) when this problem first came around, but because fo thsi problem it has had hardly any use. It's a gel battery from Iron Pony. It's on the charger now and I'll take it in tomorrow night and see what happens.

Max - that's what I've been doing and man does it ever suck! One of my problems is I only have a few hours every few days to get to it so it's time consuming as all get out. I'm about to buy all new wires just to get this damn thing figured out!! not really but that's how frustrated I am with this.

Edited April 30, 2012 by Jcarlson

[max power]

Max - that's what I've been doing and man does it ever suck! One of my problems is I only have a few hours every few days to get to it so it's time consuming as all get out. I'm about to buy all new wires just to get this damn thing figured out!! not really but that's how frustrated I am with this.

yeah, its definitely time consuming, but be patient and keep after it and you'll get it. Check your battery ground too. If its corroded, it could be draining your battery.

[Jcarlson]

Battery ground wire is new last year so I know that one is clean, but I have give to due diligence so I'll check it too.

I had the battery checked at Advance Auto and Iron Pony. It's a Bikemaster Gel battery. Advance's machine said 12.6V and 174 CCA. I.P. parts counter had a voltmeter as old as my bike but it read 12+V as well. So, all is clear on the Western Front as far as that goes.

Tomorrow is a new day so I'll keep on digging. I'll strike oil yet!!

Jim

[Jcarlson]

Here is what I found today. There are three plugs in the wiring harness up front. One is the starter/kill button, one is the turn signal/hi beam/horn, the third is the gauges.

Starting at square one - battery with key off has 12.47V. Key on it drops to 11.8xV very quickly. Key off it slowly climbs back to 12.47V.

Unplug gauges. Key on volts drop very quickly. Reconnect gauges.

Unplug turn/horn/ hi beam. Key on same thing - drops very quickly. reconnect turn/horn/hi beam.

Unplug starter/kill button. Key on it drops very slowly from 12.47V to 12.20V before I turn key off. Reconnect starter/kill button.

Now that everything is back to normal, just for kicks I turn key on it drops very quickly from 12.47V to 11.8xV.

One more thing - I did NOT unplug gauges and turn at same time. I guess I should have just to get a full test.

I don't know didly about electrical but I'm guessing it's either the starter/kill button or something in that circuit - button, solenoid, starter, coils.

Any thoughts?

Jim

[scottb]

Do all the light bulbs function? When the voltage regulator failed on my 1982 GS 850, it caused an over charge condition and allowed 18 volts to reach the battery. This over charge cause my head light, 2 cluster lights and the tail light to burn out. It might be a slight short to ground cause by melted wire insulation in the harness.

As for the slow cranking, could be the positive battery cable to the starter?

I replaced my regulator with a brand called Rick's Electric. Also, check out a website called GSResources.com. There is a garage section that contains the factory wiring diagrams for the charging system that will help you logically trace down the issue.

[scottb]

Also, if the battery is fully charged, the voltage will drop a bit with the key on, engine off due to the headlight and tail light coming on with just the key on.

[max power]

Id start with the starter cable. Clean the connections very well. Check/clean up the starter ground.

Do test again.

[Jcarlson]

Ok Max. That'll be my agenda for tomorrow night. Thanks!!

Jim

[mello dude]

Can you start the bike? See if you can do the checks in post #3. -- Its not that unusual to drop half a volt on a battery of a non running bike. Part of the puzzle is to find out if your are getting a charge on the bike while running.

[Jcarlson]

Mello Dude - it'll run. It runs great actually for a 30 year old bike. I'm wanting to test the stator/RR but that's a three handed operation and I don't have that, but it's on my to-do list for sure.

That's a large part of the problem. It's not recharging while running, but it also just draws juice while not running with the key on. I know it should draw juice without running (lights and whatnot) but not so much to where it won't crank the starter enough.

It'll start and run on full charge, but shut it off and I'm done - not enough juice after that. But I'll check stator/RR when I get the chance.

Jim

[Jcarlson]

Well folks its confirmed. Its the Stator. I did the checks as per Clymers. At 5k RPM I got 12.97V at the battery - should have gotten 14-15.5V. I did the no load test on the stator and got no reading whatsoever. I did that test three times and got the big goose egg everytime.

I know some of you suggested this a few posts ago. I was hoping that wasn't it because it just didn't make sense plus I just replaced it with a brand new one two years ago. I'll bet it doesn't even have 500 miles on. But, it is an aftermarket stator so you never know.

I pusrchased another from a different source this time. It'll be here in a few days so I should ahve it in by next week. Hopefully that solves my problems.

Once again thanks to all who chimed in. You help and suggestions were greatly appreciated. Time to put this thead to rest!!

Jim

[scottb]

Congrats on getting this sorted out. We will have to get the 2 GS's together so the Wonder Twin Powers can activate.

[mello dude]

I give up.. good luck ..

[Jcarlson]

Sorry guys, not to beat a dead horse but the Stator aint it. I replaced it today and it still isn't recharging. R/R has been replaced too. I put a fully charged, good battery on it, it started just fine, ran about 5 minutes then shut it off. Waited one minute and started it again. Ran for a few minutes and shut it off. Waited five minutes and tried tostart but battery didn't have enough charge. Waited 30 minutes and it started. Shut it down, wont start now.

I'm at wit's end with this thing. I don't know what else to do shy of replace everything part by part until I solve it.

Anyone wanting to stop by and help, PM me and I'll give you my address.

Jim