Strange electrical problem

[Mrlimeedk]

It seems something is draining my battery even while the ignition is off, this morning i had to run the bike to get it started because the battery was nearly dead.

Here comes a bit of backstory, the bike has been running amazing since i rebuild it about 3000km's ago, during the rebuild i did change the blinkers out for led blinkers and i also put in a new smaller gauge cluster so i have changed some of the wiring up front, the blinkers where pretty much plug and play apart from having to get a new led blinker relay and restricting the direction the electricity could run when going to and from the blinker indikation led's. Now as i said these changes have been functioning perfectly for the last 3000km's.

Then here's when the problem starts, i was recently on a long trip with the bike, and one evening on this trip we had not arrived at our destination so we were riding in the dark when suddenly my headlight dies, i switched to highbeams and that was still working so i just suspected a blown bulb. We finished the trip and i had no further problems apart from the blown bulb.

A couple days pass and im out riding again, still havent replaced the bulb when i suddenly notice my blinkers have a irregular blinking rythm, like they were slowing and speeding up randomly. At this point im thinking maybe the blown bulb is doing something weird to mess with my blinkers, so i get the bulb changed and my headlight is back to regular working order, blinkers are still acting weird tho. I go out to ride again the day after and the blinking pattern is no longer irregular but just slower than usual. Day after that i go out riding again and suddenly the blinkers completely stop working, i turn off the bike and turn it on again and they are back. Then comes today, turn the ignition on and check the blinkers, they are still working, then try to start the bike but the starter only barely turns over the engine, no where near enough to start it. So i run start it and it roars to life instantly, i run it for a few minutes turn it off and try to start it again, this time it starts on its own but the cranking still feels weaker than usual leaving me with the impression that the battery either is bad and losing charge overnight or somethings up with the electrical system, draining the battery while turned off.

Sorry for almost telling you guys the entire life story of my bike, but i felt it was important to get all the details when dealing with an electrical problem like this 😅.
On a final note the the battery was bought new sometime last year, but then sat for about 6 months without being charged before i revived it 2-3 months ago, and it has been running strong until this problem started.

Any ideas on what could be causing the problem would be much appreciated!

[Brendan W]

Hi Mrlimeedk and Welcome

I suspect that your problem centers on the battery and the charging system.
Charge the battery fully. Try to start the bike and measure the voltage drop when cranking. If it goes below 10 Volts you may have a problem with the battery.
With the bike running what voltage do you see at the battery terminals. I would expect about 13 Volts at idle rising to 14.4 at 5000 rpm.
Blowing a bulb can be a sign of excess charging voltage which over time could warp the battery plates and reduce it's performance.

[Grimly]

I suspect your regulator has been playing up for a while.
It might be nothing more than a couple of bad connections.
Time to break out the multi meter.

[Gorminrider]

Battery drain overnight? a bad battery can also self-discharge very quickly. I don't see how you could get far with a bad charging system and hi-beam on but check for charging voltage of 13.8 to 14.8 volts across battery when bike idling...

parasitic drain key off?
You can attach your multimeter as an ammeter with the bike key to OFF. Nowadays, many have an UNFUSED 10 amp option, but a simple small (12volt lightbulb with wires attached will do. a small dash-light is best because larger bulbs will not glow for small "leaks".

First, take out your main fuse and connect the meter across it's empty connections. If nothing definite shows on the meter change down to 250ma on the meter.

If you get a reading or a bulbglow either way, you have leakage in the bike's electrical system and can move onto inserting your ammeter into the circuit of devices that are connected without the key on...the Reg/rectifier perhaps or something incorrectly attached to the red wires on your bike. Also the key switch itself may be faulty...allowing some power through a bridge of corrosion...

But

so i have changed some of the wiring up front

rings abell.
Personally I suspect your relay and signal connections too. Since it's aftermarket, did you connect it to the correct fuse? Pull the turn-signal fuse and it should not work at all, if correct.

And need say, a cheapo three-lead relay can fail quite easily anyways...some go forever, some do not.

[Mrlimeedk]

Hey fellas, so i finally got around to doing some work on the bike today, i started by measuring the voltage with the ignition off, here it measured a steady 13.80, i then switched the ignition on and the voltage dropped to 12.50 and was slowly getting lower and lower. Then i measured while trying to start the bike and here the voltage dropped to zero and the starter just gave a single click. After that i got the bike started to measure the charging volts, and at idle it measured around 14.30 average, and giving it a little throttle it shot up to around 16-17 volts? It seems a little high to me, could that be what is killing my battery?

[Steve]

With the voltage dropping to zero when trying to start the battery, I would strongly suspect what is essentially a dead battery. OK, it's only MOSTLY dead, but still needs to be replaced.

With the voltage shooting up well over 15 volts, you also have a dead Rectifier/Regulator (R/R). The faulty R/R has not been helping your battery life at all. I would suspect that if you have a standard wet cell lead-acid battery, it has been boiled dry.

We have found that the R/R from a Polaris RZR side-by-side or a SeaDoo personal watercraft works much better than stock. Either way, you would be looking for the Shindengen SH775 R/R that is used in both of those vehicles. It's not exactly cheap if bought new, but good used examples are rather common on eBay. The problem with finding them on eBay is that there are way too many Chinese fakes available that look rather similar. One easy way to filter them out is to only search for "USED" items, not "NEW". Not sure what the market would be in your country, but here, they are usually in the $40-70 range.

.

[Mrlimeedk]

I have a spare oem regulator laying around from another gs scrap bike i have been using for spare parts, so i recon i'll try throwing that on for starters to see if its any good. Then im gonna keep a look out for one of those SH775 units, now if i where to get one of those how would i go about doing the wiring they look to have two connectors with 5 pins in total from what i can see.

Also when you say they work much better in what way do you mean? Are they better at keeping the charging volts down, do they last longer or whats up with those? I'm curious!

[Brendan W]

Beware of spare oem r/r units lying around.
The local breaker gave me five for free to see if I could find a good one.
I didn't.
The oem units allow the generator to deliver high current all the time and any excess is dumped back to the stator windings. Over time this causes stators to burn when the regulator fails. Failing regulator also kills batteries as the excess voltage will deliver too much current and boil the battery and warp plates. They are called shunt regulators.
The 775 switches the charging current off when not needed. The switching frequency is high enough for our machines. This is called series regulation.

[Mrlimeedk]

Well i suppose i better get one of those 775 series on the way then, sounds like the oem solution was somewhat flawed from the beginning.

[Brendan W]

Well i suppose i better get one of those 775 series on the way then, sounds like the oem solution was somewhat flawed from the beginning.

In fairness, I don't think that the designers and builders had any idea that these machines would last this long

[Grimly]

Well i suppose i better get one of those 775 series on the way then, sounds like the oem solution was somewhat flawed from the beginning.

They were flawed, but the semiconductors that would have worked in a series design weren't available, and even if they were, they'd have cost a packet (and probably still gone pop sooner or later).
30+ years of semiconductor development brought us the series reg at a reasonable price, and stone-reliable too.
Looking at it from Suzuki's point of view, they furnished the bikes with a working charging system that was reliable enough as long as the owner kept up the maintenance. Of course, most owners didn't and by the time the bike was in the hands of the second or third owner, the connections on the charging system were starting to corrode and lead to the breakdown of the system, in a pack-of-cards fashion.
By that time, the manufacturers didn't care - the bikes had already proved themselves as bullet-proof mechanically, and Suzuki sold many hundreds, if not thousands, of replacement stators and regulators - still with the flaw in them, of course. On and on it went...
The only exception to this was hearing of the suitability of some Honda regulators, which seemed to extend stator life - unless you ran the bike without lights on, and that was the death knell of the stator, once again.

[Mrlimeedk]

I got the extra regulator i had laying around thrown on, and its now showing 13.3 volts at idle dropping towards 12 volts when revs rise, now i know some of you said it should rise towards 14 volts when revved, so does that mean this one is broken aswell or is it okay for it to drop towards 12 volts? 🤔

[Rich82GS750TZ]

No, 12+V is not enough. You can do the quick test and post up all 6 numbers (link in my sig), also you can read all about what you're most likely headed for in my charging system story also linked in my signature. This should give you a pretty full picture. There are many stories here just like it.

[Mrlimeedk]

Alright just got finished reading your charging system story and oh boi am i dreading what lays ahead of me �� i dont really have any more money to put into the bike at the moment, so i guess ill try getting all the connections checked and cleaned as a beginning. Also, before i changed the R/R i was sitting at 14.3 volts at idle rising towards 17 as the revs climbed, and now after i changed the R/R im sitting at 13.3 volts at idle dropping towards 12 when revved any ideas of what could be the culprit would be much appreciated. I wish i could pull it all apart and get it sorted proberly but i sadly dont have the time nor the money right now

Edit:
Nvm about me asking what the culprit of the dropping voltage could be, i read the 6 step test again and realised it specified that a drop in voltage from idle to 5000 rpm is most likely bad connections.

[Rob S.]

...oh boi am i dreading what lays ahead of me...

I heard that. Even though my charging system has worked properly in the 7 years I've owned her, I dread what could lie ahead, or what would be revealed if I investigated.

I paid only $1500, but have since put untold thousands into her. Owning a 40-year-old motorcycle is no cheap option.