Idling lighting issue...

[BigDaddyD]

I'm having trouble with my turn signals and lighting when my bike is at low idle.

I have a '77 GS750 and I'm assuming the headlamp is a stock or stock replacement, nothing crazy. My Turnsignals however, are aftermarket and are dual-filament (biker's choice dual-filament bullet-style signal) which I have set up to run as parking lights when when headlamp is on, and then the 2nd filament is used when turning.
(I think I just spliced into the headlamp and tail lamp positive wire and then grounded them to the frame, the blinker filament runs off the normal setup)

My problem is, when sitting at a light with my turnsignal on, sometimes they won't blink, and when they do it's very very slow.
This seems to happen mostly at night when I have my headlight on.
When I rev the engine the blinker will work better and my headlight gets brighter, so I'm assuming I either have too much of a load on the lighting circuits that the Turnsignal Solenoid isn't working, or it's something in my charging system.

My battery seems to stay charged fairly well, however, if my bike hasen't been run in a while (3-4days normally) and is requiring a little extra cranking to get fired up, the battery does run out.
So there is the possibility my battery might be going bad.
But I wanted to check with you guys before I went out and bought a new battery.

What do you guys think I should start looking first?

[duaneage]

I suspect low voltage from the RR. This could be caused by a weak stator with a bad leg, a bad RR, or bad connection throughout. Or all three. I would start with the red lead from the RR and follow it to the fuse box. If the bullet terminals are corroded replace with new bullets, use a volt meter and see how much voltage you have at the red RR lead and start following it.

Connect the meter lead to the engine ground or a frame bolt. Don't assume the battery is the best ground. if you have less than 12.5 volts at the red RR output wire stop the bike, switch off, then remove the headlight and turn signal fuses. Test again. Without any lights it should climb up to around 13.5 or higher. If not, the RR and /or stator are not working well. The three wires from the stator might have corroded or burnt connectors, a sign of RR trouble.

IF they pass this test move on to the ignition switch. Everything goes through here after the fuse block. Find the green connector in the headlight and measure (keep the same ground connection as before) and check the orange wire and red wire for voltage. If you see a big drop between them the ignition switch needs to be cleaned (the electrical parts need scrubbing).

If this test passes go to the grounds for the turn signals front and back and clean the rings that are behind the mounting bolts. Try also cleaning the sockets.


I offer a Honda upgrade RR kit that solves a bad RR problem. For 40 dollars it will replace the OEM Suzuki RR with a more robust Honda unit that is a bolt on unit. PM if you find you need one.

[BigDaddyD]

At the risk of sounding horribly dumb...
What's the "RR"?

[chef1366]

Read over the stator papers. http://www.thegsresources.com/gs_garage.htm
You have a seperate retifier and regulator. The rectifier takes A/C and changes it to D/C. The regulator keeps it below 14.8 volts so to not fry your electrical system.
Usually the rectifier is located by the fuse block and the regulator is near the battery box. With an R/R from duaneage you won't need the rectifier. They became one unit around 80.

[SqDancerLynn1]

RR is a combo regulator - rectifier. Hi BigDaddy Is that the bike I sold to you ? If it is let me know & i will send you a RR. If it is the same battery it is 5 years old, may need replacement

[bakalorz]

I suspect it's a combination of a couple of things.

First, the GS's don't have a lot of extra electrical capacity to begin with.
Even with a properly functioning charging system, a slight voltage drop when idling is not abnormal, meaning that they are partially running off the battery when idling.

And it sounds like your battery may be on the way out.
Running off the battery occasionally won't cause any problems with a healthy battery, but with a marginal one, it can't really support the temporary load too well, and the voltage drop is larger, leading to your symptoms.

That problem is definately increased by using dual filament bulbs.
The second filaments are not a huge load, but they are not insignificant either (probably over 2 amps total for 4 of them)
On top of an already marginal system, they may be the straw that breaks the camels back.

Finally, you mentioned a "low idle". If your bike is running great, and idles exceptionally low, that will definately cut into the charging current available at idle.
I'm not trying to say you should idle at 2000 rpm, but if your bike is at the low end of the range, adjust it up toward the higher end of the recommended range.
(for example, off the top of my head, if you are at 900 rpm, take it to 1100).

I suspect it's pretty unlikely to be a problem with either the stator or the R/R itself.
If the stator is bad or one of the diodes in the R/R is bad, (you can do the stator papers diode check too test it) then you would get your symptoms, but I would find it likely that you would also have lots of other problems rather than just at idle
(battery always being dead, and killing new batteries pretty quick, etc.)
Other types of problems with the regulator would tend to cause overvoltage at high RPM rather than low voltage at idle.

Bad connections in the charging or the turn signal system are certainly a possiblity, and should be checked to be thorough; but I suspect that you won't find much wrong there.

----

I would first try just checking the connections (just to make sure),
and bump up the idle a bit.
(if its not already at the the high end of acceptable)

After that I would probably try replacing the battery since it sounds like it may be marginal.

If none of that works, then go through the stator papers; but I suspect your charging system is working properly.
(also; please note that if your charging system is working properly, putting in a better R/R will not increase your available current/voltage. The idle current is determined by the stator, and the R/R only acts to regulate the current/voltage when the RPMs get high enough that the voltage/current would be too high otherwise)

And finally, it's possible that the running lights may just be too much of a load for your system to handle.
(but I would bet that with a good battery they won't be a problem)

[BigDaddyD]

RR is a combo regulator - rectifier. Hi BigDaddy Is that the bike I sold to you ? If it is let me know & i will send you a RR. If it is the same battery it is 5 years old, may need replacement

Thanks Lynn,
Yeah, it's the same bike. I've gotten her pretty well fixed up with the help of RapidRay down in the O.C. and she's been running fairly well for almost a year now. I'm pretty sure you threw in an extra Regulator in that box of parts you gave me. I think I'm gonna go grab a voltage tester and go thru my system before I replace anything. I'll keep you posted! Thanks for the offer though!

I suspect it's a combination of a couple of things.

First, the GS's don't have a lot of extra electrical capacity to begin with.
Even with a properly functioning charging system, a slight voltage drop when idling is not abnormal, meaning that they are partially running off the battery when idling.

And it sounds like your battery may be on the way out.
Running off the battery occasionally won't cause any problems with a healthy battery, but with a marginal one, it can't really support the temporary load too well, and the voltage drop is larger, leading to your symptoms.

That problem is definately increased by using dual filament bulbs.
The second filaments are not a huge load, but they are not insignificant either (probably over 2 amps total for 4 of them)
On top of an already marginal system, they may be the straw that breaks the camels back.

Finally, you mentioned a "low idle". If your bike is running great, and idles exceptionally low, that will definately cut into the charging current available at idle.
I'm not trying to say you should idle at 2000 rpm, but if your bike is at the low end of the range, adjust it up toward the higher end of the recommended range.
(for example, off the top of my head, if you are at 900 rpm, take it to 1100).

I suspect it's pretty unlikely to be a problem with either the stator or the R/R itself.
If the stator is bad or one of the diodes in the R/R is bad, (you can do the stator papers diode check too test it) then you would get your symptoms, but I would find it likely that you would also have lots of other problems rather than just at idle
(battery always being dead, and killing new batteries pretty quick, etc.)
Other types of problems with the regulator would tend to cause overvoltage at high RPM rather than low voltage at idle.

Bad connections in the charging or the turn signal system are certainly a possiblity, and should be checked to be thorough; but I suspect that you won't find much wrong there.

----

I would first try just checking the connections (just to make sure),
and bump up the idle a bit.
(if its not already at the the high end of acceptable)

After that I would probably try replacing the battery since it sounds like it may be marginal.

If none of that works, then go through the stator papers; but I suspect your charging system is working properly.
(also; please note that if your charging system is working properly, putting in a better R/R will not increase your available current/voltage. The idle current is determined by the stator, and the R/R only acts to regulate the current/voltage when the RPMs get high enough that the voltage/current would be too high otherwise)

And finally, it's possible that the running lights may just be too much of a load for your system to handle.
(but I would bet that with a good battery they won't be a problem)

Hi Bakalorz,
Yeah, originally when I noticed the problem a lot it was when I had the bike idling closer to 1000rpm. I've since bumped it up a little closer to the 1500rpm mark and that helped a little. I've never noticed any other electrical issue with the bike idling, or at speed, which is why I originally thought it may either be the battery like you mentioned (and as Lynn has mentioned earlier it's probably over 5yrs old) or possibly that the system can't handle the extra draw. I've already pretty much gone over the entire electrical system and haven't noticed any bad connections or grounds, so I think I'm safe there.
My battery has never been ALL THE WAY dead. Like I said earlier, it'll definitely drain fast when cranking a cold engine, but I've never gone down to the garage to a dead battery, even after sitting for over 2 weeks.

[Matchless]

Make sure you have 23 watt bulbs in the front and rear. I had the same problem and found a 10 watt in the rear. Not enough current to properly operate the flasher unit!