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Main Area => General GS500 Discussion => Topic started by: cpaiin on September 17, 2011, 11:57:49 PM

Title: GS500 Electrical problem
Post by: cpaiin on September 17, 2011, 11:57:49 PM
Hi, first post here, so be sure to lemme know everything I'm doing wrong by posting here on the forum ;)
So here's the problem:
My battery seemed to be dying, so I went and bought a new one.  I took out the old battery and had the new one all ready to go. Without putting the cords to the battery terminals, I dropped the new battery into place.  I put the first cord on one terminal, and then only touched the second cord to the other terminal.  As soon as I did this, it sparked.  I took out the battery and realized the terminals on the battery were backwards   :cookoo:
So now, I'm at a loss.  I have yet to buy a correct battery with the terminals on the correct side so I don't know if a new battery will solve the problem.  Taking a guess, I would say that something more than needing a new battery will be the fix.  I tried putting my OLD battery back in, but nothing would even turn on.. no light, nothing.
The weird thing is, I could push-start my bike, and it would stay on, but hardly.  The lights were flashing to the rhythm of the motor. The even WEIRDER thing is that squeezing the front brake made the engine work better, sounding more reliable..

Any ideas what the problem might be and how to fix it??
Thanks :)
Title: Re: GS500 Electrical problem
Post by: adidasguy on September 18, 2011, 12:28:48 AM
If it runs, your ignitor box is probably OK. As for other things, there are a few diodes in the circuit if you look at the wiring diagrams. You can check those with a volt meter (FYI: check resistance - diodes conduct in only 1 direction so set meter for continuity setting or something like 1000 ohm resistance scale). Diodes could have been fried from the reverse current. Unplug them to check them.

Others may have some additional suggestions. As for the right battery - I prefer to pay the extra and get a good, correct battery. Lots of us buy from batterystuff.com

FYI in case you don't have it: (If your bike is older, then the tach is mechanical, not electronic, and you won't have a throttle position sensor)
(http://i1206.photobucket.com/albums/bb442/adidasguy/Assorted/SCAN0004_smaller.png)
Title: Re: GS500 Electrical problem
Post by: the mole on September 18, 2011, 04:11:48 AM
You can either return the battery and get the right one, or modify your battery connections to fit the one you have. First thing I would check is the one and only fuse (20 amp).
Title: Re: GS500 Electrical problem
Post by: bigfatcat on September 18, 2011, 05:50:32 AM
If it were me, first thing would be buy an automatic battery charger - almost a necessity especially if u let your bike sit for appreciable periods without riding .... try to put a charge on the old battery overnight - if it takes the charge problem solved and u have a charger for future use.

If battery won't charge, then a new battery, preferabley AGM type (Absorbed Glass Mat) - for me cheap small batteries for lawnmowers, bikes, atv's, etc don't seem to hold charge well much more than a few days - hence the battery charger suggestion.

In any event, you need a good condition, fully charged battery for the bike to start easily, and run well, or to diagnose electrical problems.
Title: Re: GS500 Electrical problem
Post by: adidasguy on September 18, 2011, 11:23:00 AM
Quote from: bigfatcat on September 18, 2011, 05:50:32 AM
If battery won't charge, then a new battery, preferabley AGM type (Absorbed Glass Mat) - for me cheap small batteries for lawnmowers, bikes, atv's, etc don't seem to hold charge well much more than a few days - hence the battery charger suggestion.
I have no problem batteries holding a charge - even with the standard lead acid ones. Then I don't buy the "cheap" batteries, either. Now I'm using the LiFe batteries - which hold a charge for a year. There is something wrong if a battery won't hold a charge for more than a few days because that's what batteries are supposed to do: hold a charge. (Maybe you're always putting your bike into "park" so the tail light is always on - hence your battery gets drained?)

Fuse: good to check that, too. Also possible the voltage regulator is fried. Bike may run strange if voltage is too high from the generator and the regulator isn't working. The brake light on would add a little load and lower the voltage slightly. You can check your headlights. If they are blowing out, then voltage regulator is gone. actually the voltage regulator can fry 2 different ways: one is not not let any voltage through. The other is to let everything through and not regulate the voltage. I  had one go out. Revving engine would take voltage over 19 volts and the headlight would blow. Grab your meter and see what's happening.
Title: Re: GS500 Electrical problem
Post by: crzydood17 on September 18, 2011, 12:42:21 PM
sadly if the bike can be push started then its not your fuse... I know this after someone recently tried to hot wire my bike and after fixing the cut ignition wires I tried to jump it thinking it was dead, after pushing it up and rolling down a hill for 20 mins I checked the fuse and it was blown. So if it runs at all it should not be a fuse issue, unless the pre 2004's were different somehow...

as far as the battery backwards is concerned... you basically short circuited the entire bike... who knows where it failed at that point... put a battery with some sort of a charge in (doesn't have to be enough to start it just to push some juice through the lines). Test from the battery to the fuse, across the fuse then keep following the power wires, test everywhere you can...
Title: Re: GS500 Electrical problem
Post by: cpaiin on September 18, 2011, 02:25:34 PM
Thanks everyone for the suggestions. 
I tested the fuse and it's fine, so crzydood17 is right.
@adidasguy , the bike starts, so if the voltage regulator is blown, it would have to be letting everything through, right??  I'm a bit afraid of starting it up again if there's the chance of wrecking anything else.  thanks for the diagram.  maybe if I look at it long enough, i'll begin to understand it :)
I have a charger that auto stops when the battery is full. I put it on overnight, and kept it on the whole next day, but the charger never turned itself off.  I checked the voltage on the battery, and it was over 13 volts.  I'm thinking the battery isn't in great condition. 
My plan of action for now is to get a new battery and start testing all over the place.  I'm not too sure on exactly how to test these things, so if anyone has suggestions, let me know.  I have a simple multimeter that can check ac/dc voltage, amps up to 10amps, and resistance (is this the same as ohms?)  I don't think I have a way to change the ohm scale, and I'm not sure which side (red or black) should be closest to the battery.. hopefully I'll be able to figure things out
Let me know if you have any more ideas
Title: Re: GS500 Electrical problem
Post by: adidasguy on September 18, 2011, 03:32:18 PM
I ran for a day with the voltage regulator fried. While low RPM your generator puts out 10-14 volts, at high RPM it goes up to 18 or higher. That's when the headlight blew. Nothing else went out since everything else is LED and voltage is not as damaging to them.

Turn on the bike and start it up. Check voltage at the battery. If voltage goes over 14 volts when revving it, then regulator is bad.

If a digital meter, then polarity of terminals is not critical - it will just display a negative voltage. Generally red=positive, black=ground.
Ohms=resistance. Don't check resistance with things on or battery connected. Only need resistance to check if diodes are bad (which could prevent bike from starting with the starter button). Diodes control starter relay: clutch in, in neutral, side stand switch. You can trace that on the wiring diagram. If they're blown, starter relay might not get engaged but you could still push start it.
Title: Re: GS500 Electrical problem
Post by: cpaiin on September 18, 2011, 05:52:42 PM
Thanks adidasguy

So I just got my battery and push-started it one more time.  I rev'd the engine and checked the voltage (by putting the two connections on the battery terminals) and it read under 13Volts the whole time!  That should mean that the voltage regulator isn't broken :D
Hopefully that narrows it down to just the diodes. 
Looking at the diagram, it looks like the wire setup isn't quite where the parts are placed on the bike..  would anyone know where these diodes are located on the bike? And for a replacement, any special type to buy or place to get them from?
Title: Re: GS500 Electrical problem
Post by: cpaiin on September 18, 2011, 09:10:04 PM
Hold up, I'm confused.   :icon_question:  The diode is what keeps a bike from starting when the kickstand is down, clutch is out, bike's in gear.. I'm able to start my bike if I push-start it.  I'm not confused about that.  I'm confused about why the engine doesn't seem 'stable.'
For example, the bike doesn't want to stay on.  It's gotta have full choke for it to stay on.
Another thing is that the headlights, or any of the lights, don't work when the key is in, bike on, but the engine off.  If I start the bike up, the lights pulse 'to the beat of the engine' and are very dim.  Would a broken diode affect this?
I also noticed that the tachometer doesn't continuously function.  It will read the RPMs then stop, then show a reading again.
The last thing is that the engine works significantly (but not completely) better when I pull on the front brake handle (?!?!?!?)
So could diodes affect all this? or do they only affect the initial start of the engine?
Thanks again everyone.  I really do appreciate your help!!
Title: Re: GS500 Electrical problem
Post by: adidasguy on September 18, 2011, 09:57:08 PM
Push start is not the same as pressing the start button and the starter motor turning the engine. You can puch start a bike even if you were to remove the starter motor. So defective diodes that prevent the starter relay from engaging and making the starter motor go has no effect on whether the bike will run after push starting it. Push start is just "go fast and pop into gear" and doesn't involve the starter motor or starter relay at all.

Broken diodes could be causing a drain. Then you can have other problems. By the wiring diagram, everything on the bike is on one side of the fuse and the battery is on the other side. So I suppose you could push start a bike and have it run as long as the RPM's were high enough to generate enough electricity. If the fried OR one of the wires from the battery is fried, then you might see what you're seeing.

Check resistance from negative battery terminal to some other ground point on the bike - should be nearly zero ohms.
Check the +12 from the battery to the fuse. Should see voltage about same as on the battery (negative meter probe on negative of battery). Set meter for 20v DC or higher. measure battery. Then measure at each side of the fuse. Zero somewhere means fried wire or fuse.

Wiring diagram + volt meter ----> start tracing until you find the break. Something fried. Wires can fry inside the insulation and you won't see it - especially if the wire is bundled or wrapped in tape. Also a wire can melt insulation in a bundle of wires and short to an adjacent wire.

If you are worried and want to play really safe - you can trace the +12 and other stuff by clipping on a 9v battery in place of the bike battery (couple alligator clips). Then you look for 9 volts. With the bike off, nothing should be draining the tiny battery and you can safely trace things - looking for 9 volts.

PS: The voltage regulator is also a rectifier because the generator makes AC which needs to be converted to DC. The pulsating could be due to part of the rectifier being fried so you get half rectified wave DC - meaning pulsing DC. Without the battery to act as a giant capacitor, you'll get pulsating DC voltage which will change pulse rate as the engine changes RPM's.

Don't know where you're located (it is not in your profile). That helps as there may be someone near you that can help. if you were in Seattle, I'd say come to the bike cave and we'd have it fixed in half an hour.
Title: Re: GS500 Electrical problem
Post by: the mole on September 19, 2011, 04:14:00 AM
If you run your engine and rev it a bit and the voltage stays under 13 volts then you have a problem with your charging system. It should go a bit over 14 volts when revved. That would explain the battery problems.
Title: Re: GS500 Electrical problem
Post by: cpaiin on September 19, 2011, 08:46:20 PM
Hmm, I'm starting to wonder if the battery is having ANY affect on the bike whatsoever..  I mean, I wonder if I could start the bike without a battery attached.  The new battery should be working fine, and not even the lights turn on.  Correct me if I'm wrong, but the diodes don't affect the allowance of electricity to lights.  I'm thinking that the battery shows NO change whatsoever when revving the engine, because nothing is even connected to the battery.

@the mole, I have a feeling that the charger is still working because the lights turn on when the engine is running.  They're just very dim and 'pulse' with the engine (but maybe that's just a working alternator??).

@adidasguy, I live in San Diego, CA.  Know of anyone around here who could help out?

Thanks again to EVERYONE  for your comments and help.  Hopefully we'll be able to pin this down soon!
Title: Re: GS500 Electrical problem
Post by: adidasguy on September 19, 2011, 08:55:15 PM
Time to start tracing wires with the meter. Start at the battery and continue until you get nothing. You have a fried wire somewhere, fried connector or blown fuse. Clip the negative of the meter to the frame. +12 at the battery? If no, then the ground wire from battery to frame is fried. Have +12? (12 or so, can be 11 to 14 volts) Then follow wire from battery to fuse. Check there. Continue until you get nothing and you've found the break. Use the wiring diagram. Should take all of 5 minutes to trace the couple connections from the battery to find your break.

A fuse can look OK and still be fried. Did you actually test the fuse or replace it with a new one to be sure?

Bike can be push started without a battery. People do it all the time when their battery goes dead.
Title: Re: GS500 Electrical problem
Post by: cpaiin on September 19, 2011, 09:34:33 PM
AH HA!!  It's fixed! :D 
It ended up being just a broken fuse.  The thing that stumped me this whole time is that the fuse I kept pulling out and testing was just a REPLACEMENT fuse!!! That fuse was just sticking in some rubber for if I ever needed it.  I took off the fairing and pulled off the plug connected to the fuse holder (the replacement and the one being used are in the same unit) and the real fuse was under cap of the plug.  It was so surprising. And when I found that the real fuse was broken, I pretty much new it had to be the problem.

Thank you ALL very much.  I feel really stupid to have been duped by the fuse the whole time, but I'm just glad it's fixed and it was cheap (well, I got a new battery, but I probably needed one anyway)

Thanks again!
Title: Re: GS500 Electrical problem
Post by: adidasguy on September 19, 2011, 09:42:27 PM
Piece of cake! (http://cdn.pnwriders.com/images/smilies/wav.gif)

Consider this: lots of people don't know there is a spare fuse! You do!
Title: Re: GS500 Electrical problem
Post by: FJCharlie on September 20, 2011, 07:13:56 AM
what Amps fuse should be there?
im having weird problem with lights, its normal before i brake or use turn signal. then headlight starts to flash-when turn signal flashes light is a bit dimmer, when turn is off its bright, and so on. same with brake, i pull brake headlight is dim, its on but just loses power...
then i checked fuse, it was 15amps! way weak fuse, so i used 20, it melted. ok i try with another- 20amps melted, so i got 25amps, it was fine till the other day, same thing with lights- havent checked fuse.
before fuse swaps i used multimer digital and i checked alternator-goo 75-80v so its ok, checked rectifier it was ok too. so it must be a fuse or ground. checked ground wires (right side of motor) both fine, any other grounds on bike i should check?
so next is fuse, im thinking of 30amps? thats the reason i asked what amp fuse did you use? it rhymes :D
tnx in advance
Title: Re: GS500 Electrical problem
Post by: applecrew on September 20, 2011, 08:30:07 AM
Pretty certain it's a 20-amp fuse. If you're blowing through that, you do have a problem. Trying bigger fuses does not solve the problem, it just increases the likelihood of having your wiring harness go up in smoke, and I hope you're not on it when it does!

You've probably got an open circuit somewhere (i.e., short).

my $0.02

Mike
Title: Re: GS500 Electrical problem
Post by: FJCharlie on September 20, 2011, 11:07:36 AM
any suggestions?  :dunno_black:
Title: Re: GS500 Electrical problem
Post by: adidasguy on September 20, 2011, 11:43:38 AM
20 amp fuse.
If turn signals make lights go dim, then you have shorts developing in the wiring for the turn signals.
Trace those wires. Unplug turn signals one at a time. You don't say whether both left and right. Don't say what model bike you have. Don't say what electrical mods you've made (turn signals, headlight, etc.)

When does fuse fry? When you put on brake or turn signals or always? Knowing that will help isolate things.

If older bike, wires can be scraped and starting to short in the headlight bucket.
Any model, wires could be getting scraped against the frame OR by something hot and insulation is going out - causing shorts.


Title: Re: GS500 Electrical problem
Post by: FJCharlie on September 20, 2011, 12:43:03 PM
thanks for responce.
i have 91 gs500, no mods were done-that im aware of.
left or right turn signal on headlight is dim, brake without turn signals-same thing, when combined way dim...
will make sweep through headlight harness, tnx for this one  :thumb:
first i thought it was headlight bulb so i changed it-no fix
i will use wd 40 on all contacts and report if breaktrough
Title: Re: GS500 Electrical problem
Post by: cpaiin on September 20, 2011, 09:15:12 PM
The same issue also happens to me.  Your problem could be totally different since I'm not sure how dim your headlight can get, but I always assumed this was normal.  It's hardly noticeable for me, and doesn't affect my ability to see while riding at night.  I gathered that the increased amount of power (going to the turn signals and/or brakes) just created less power to the headlight.
Title: Re: GS500 Electrical problem
Post by: the mole on September 21, 2011, 03:06:45 AM
FJ, +1 to applecrews comments. If the standard 20 amp fuse is blowing you have a short circuit somewhere, if you keep trying bigger fuses eventually the wiring will act like a fuse and burn out.
If you know how to use a multimeter to trace the fault, go to it, otherwise start having a very close look at all the wiring (particularly blinkers by the sound of it) looking for frayed/chafed cables. Most likely ares are where there is movement or sharp edges, like around the steering head or where wires go through the headlight shell. Your bike is old enough for this sort of problem to occur due to old insulation getting hard/brittle.
Title: Re: GS500 Electrical problem
Post by: FJCharlie on September 21, 2011, 06:54:54 AM
thanks guys for trying to help.
i noticed this first on my tach and speedometer, like new year decoration. afterwards i saw its also diming (is that a word?) my headlight, its a tiny little bit but noticeable.. i will record a video of this and post it. my fuses melt because they are plastic ones. but from time to time lets say a month  or two it blows. i rode 2000km in 15 days trough balcan countries with no problems, was riding for several hours and nothing happened to the fuse. 20amps, then i tried 25 and it was ok no dim and stuff, but now its happening again. i will check cables, i saw someone was using duct tape alot...
any other ground wires other than 2 on the right side of the motor?
Title: Re: GS500 Electrical problem
Post by: adidasguy on September 21, 2011, 10:57:58 AM
All the fuses are plastic. They should never get hot enough to melt the plastic.
You have a problem. 20 amp is big enough for the fuse.
Somewhere you've got electrical problems. You need to take the wiring diagram and start tracing your wiring harness. Somewhere wires are either shorted, corroding or melting together.
On a proper bike, with all electronics working properly, no bad wiring, good battery,  the headlight should hardly ever change brightness except when the starter motor is engaged (it eats lots of power).
Sounds like you have a short somewhere that's sucking power, causing the fuse to get really hot almost to the point of blowing so it starts to melt. Then once in a while you pull a little over 20 amps and the fuse finally goes.

A fuse wire is a small heating element. As current flows through it, it heats up. At the 20 amp point, it heats enough to melt the wire inside. That the plastic is melting means you're pulling near 20 amps all the time - which is not what your bike should be using. Over 10 amps maybe to start it. After that, your bike should only be using a couple amps while running.

PS: If your wiring harnedd has lots of duct tape - someone has really fuggled it up.
Probably cheaper to buy a good used wiring harness for $10-$15 and replace the whole thing. On ebay, pinwall cycles is a really good, reliable bike breaker out of Ohio. Bought kinds of parts from them. Never had a problem, part always clearly photo'd and described,  and never been disappointed.
Title: Re: GS500 Electrical problem
Post by: FJCharlie on September 21, 2011, 07:09:27 PM
here we go...
tonight when going back from work i recorded my problem...
tach lights are not as weak as shown in video...
http://www.youtube.com/watch?v=G2wwgKzCf-s
Title: Re: GS500 Electrical problem
Post by: adidasguy on September 21, 2011, 10:31:55 PM
You do have an electrical problem.
Measure the voltage at the battery terminals. What is it....
1. With bike off
2. Bike turned on, not running
3. Bike running
4. Bike running with brake on
5. Depending on how fast your meter updates (if digital) it might be hard to measure the voltage difference with turn signals going, so brake light on should give an indication, but try with turn signals going.
6. How does voltage change if you rev to 4k RPM compared to idling at 1200 rpm?

You can also try doing same test measuring voltage somewhere on the front of the bike, like at the input to the high/low beam switch (or the connector to it) as that will be the exact voltage going to the headlight.

Possible the voltage regulator is going out and your voltage is high then drops down with additional load of the turn lights or brake light.

Another possibility is bad battery. Battery should act like a whopping big capacitor. With a slight change in load, voltage should not change.
Title: Re: GS500 Electrical problem
Post by: FJCharlie on September 22, 2011, 06:11:44 AM
allready measured voltages when was checking for error. accu was brand new (used 12 and 14amp accus-so 2 in total), measured off and on state (idle) and at 5000rpm by manual. also measured alternator and rectifier/regulator at same conditions. it was all ok (manual has data about normal values)
thats the thing why i didnt give much attention to it. then i went to my mechanic, he thought its the ignition lock, he checked said its ok (ignition when faulty can eat alot of power), now i will open headlight and check all cables, but last time i was there it looked like 20 years old harness :D
you guys skip telling me if more ground wires on bike other than those 2 on right side of motor...
will remove tank seat and headlight and check all. hope for the best (i find a problem)
but im thinking ground wire is the problem, its attached to everything...
bike is running fine, lights off or on, but that dim/flash thing is anoying.. will post everything i do hopefully with good results.
addidasguy thanks for help  :thumb: