1983 GSX750E Electrical problem

[Guest]

Hi,
I own a 1983 Suzuki GSX750E. The bike runs great but lately I have noticed a strange electrical problem that I didn't have before. When the bike idles the headlight dims and if I turn on a turn signal it doesn't have the power to blink. When I accelerate, I can see more current getting to the headlight and turn signal making it blink. If the headlight is turned off and the bike is idling and I turn on the turn signal, it will blink very slowly as if it is not getting enough current. The alternator or generator does charge because I'm not having any problem with the battery.
It is really annoying when I stop at a traffic light or stop sign and have to turn left/right and the turn signal light will just stay on because it doesn't have the power to blink so I have to accelerate.
Can someone please help me solve this problem. I'm sure it is nothing major because all has worked fine.
Can it be the voltage regulator or the stator?

[posplayr]

Hi,
I own a 1983 Suzuki GSX750E. The bike runs great but lately I have noticed a strange electrical problem that I didn't have before. When the bike idles the headlight dims and if I turn on a turn signal it doesn't have the power to blink. When I accelerate, I can see more current getting to the headlight and turn signal making it blink. If the headlight is turned off and the bike is idling and I turn on the turn signal, it will blink very slowly as if it is not getting enough current. The alternator or generator does charge because I'm not having any problem with the battery.
It is really annoying when I stop at a traffic light or stop sign and have to turn left/right and the turn signal light will just stay on because it doesn't have the power to blink so I have to accelerate.
Can someone please help me solve this problem. I'm sure it is nothing major because all has worked fine.
Can it be the voltage regulator or the stator?

Do the quick test linked in my signature and report the results.

[amedeo69]

Hi Posplayr,
I performed the quick test and these are the results:
1) Key off 12.46 v.
2) key on 11.90v
3) 1500 idle 13.00v
4) 2500 rpm 13.30v
5) 5000 rpm 13.35v
6) key off 12.90v

When the motorcycle rested for awhile I remeasured the voltage of the battery and it was 11.90v.

I was trying the turn signal switch and noticed that when I turn it right, it would flash slowly but when I turned it left, the front and rear turn signal lights would just stay on. It's strange that it works for the right side and not for the left side. I removed the flasher relay and measured the current. The battery was at 11.90v and the current getting to the flasher relay while the motorcycle is not running was 11.34v. I noticed the voltage was the same either for right or left signals. Why isthe relay working on one side if it is getting the same current left or right? The relays is a nippondenso FU249SD as you can see in the pictures.

[OldVet66]

You might want to go through the electrical system and clean up all the connection points, bullet connectors, plugs, switches, grounds and lamp-holder sockets, then coat them with dielectric grease. It's not unusual for the turn signals to act like yours if the circuit does not see the proper resistance to operate the flasher. With the bike running, the flasher would probably work. Get the basics sorted out and small problems like that would go away. Then you won't be chasing your tail looking for elusive Gremlins and troubleshooting is a lot more accurate.

[Steve]

All of your voltages are a bit low. Technically speaking, 13.3-13.5 volts will keep the battery charged, but it is only a modest charge. A FULL charge will be realized with voltages over 14, usually about 14.4 volts.

As mentioned, do some cleaning in your connectors. You can also use your voltmeter to follow the power path to see where you start losing voltage. The power path goes from battery, through MAIN fuse, ignition switch, back to the other fuses, then to the various loads. With the key ON (engine can be on or off), measure the voltage at the main fuse and the other fuses. That will measure the drop through the ignition switch and all the connectors between the fuses. That will give you a starting point on where to start cleaning.

.

[posplayr]

Well Steve and old vet are correct about the connections that is all good, but I would rather continue focusing on your charging performance. Your battery is a Lilly low maybe 0.3 to 0.4 volts with key on which will probably lower your charging voltage some. The inability to get over 14.0 volts is not good and symptomatic of an issue. There are at least two things to be on the look for.
1) Dirty connections between the battery and r/r
2) stator issues.

I'm leaning toward stator issues ; generally if there are dirty connections between r/r + and battery + then you will get fold back in the voltage. The voltage at 5000 will be lower than 2500 rpm. There is no evidence of that.

I would now proceed to the revised stator pages phase a where you redo voltage tests but this time measuring the voltage drops between r/r and battery. If there are dirty connection at 5000 rpm you will be looking for over 1.0v total drop on both sides.together. I suspect there will not be that much which means the stator is going out.

To improve the voltage drops you only have to focus on grounds and the power going through the fusebox. For example the ignition switch has no bearing on charging voltage at the battery. Nothing wrong with cleaning it. I would just stay focused till you have this diagnosed.
If the voltage drops are not that large then we go to revised phase b stator tests to see what is going on with the stator.

[amedeo69]

I really appreciate your expert advice. I'm not much of an electrician but I can figure out the basics. I will try to work my way through the connections based on your advice. What does r/r+ stand for?
Where do i find the revised stator pages phase?

[OldVet66]

Rectifier/Regulator. The best replacement is a Series R/R, SH-775 or Compu-Fire.

[posplayr]

I really appreciate your expert advice. I'm not much of an electrician but I can figure out the basics. I will try to work my way through the connections based on your advice. What does r/r+ stand for?
Where do i find the revised stator pages phase?

Read the link "gs charging health" in my signature. Links to the revised as well as original stator pages are there. The typical rectifier/regulator (r/r) has 5 wires. They all have a red wire. That is r/r(+). A black wire would be r/r(-).

There are there links in a row on the same line. Read them all.

[amedeo69]

Hi,
Sorry if I didn't write earlier but I've been to busy with work. I finally got around in cleaning all the connections. My turn signal now do work even when the motorcycle is idling with the lights on. That wasn't happening before.
I followed the 3 steps of GS charging system health and made sure everything was connected correctly. I then preceeded with the revised Phase A and had to go to step 2 because at 5000 rpm the voltage was under 14v. I followed the measure positive lead voltage drop steps and it was way over 0.25V. I checked the entire lead including the ignition switch and could not find the problem.

I did the quick test again and these are my results:

1) key off - 12.30v
2) key on with lights - 11.65v
3) idle 1500 - 13.90v
4) at 2500 - 13.65v
5) at 5000 - 13.72v
6) key off - 12.50v

Quick test with lights on (if it may help):
1) 12.44
2) 11.76
3) 14.00
4) 13.48
5) 13.30
6) 12.52

I'm understanding that it isnot charging 100%. Is the problem the stator or the regulator/rectifier?
Can I continue using the motorcycle this way or will it cause a problem?

[amedeo69]

The regulator/rectifier that is on there now is a nippondenso 32800-45210. How can I check that the r/r is working correctly?

[posplayr]

Hi,
Sorry if I didn't write earlier but I've been to busy with work. I finally got around in cleaning all the connections. My turn signal now do work even when the motorcycle is idling with the lights on. That wasn't happening before.
I followed the 3 steps of GS charging system health and made sure everything was connected correctly. I then preceeded with the revised Phase A and had to go to step 2 because at 5000 rpm the voltage was under 14v. I followed the measure positive lead voltage drop steps and it was way over 0.25V. I checked the entire lead including the ignition switch and could not find the problem.

I did the quick test again and these are my results:

1) key off - 12.30v
2) key on with lights - 11.65v
3) idle 1500 - 13.90v
4) at 2500 - 13.65v
5) at 5000 - 13.72v
6) key off - 12.50v

Quick test with lights on (if it may help):
1) 12.44
2) 11.76
3) 14.00
4) 13.48
5) 13.30
6) 12.52

I'm understanding that it isnot charging 100%. Is the problem the stator or the regulator/rectifier?
Can I continue using the motorcycle this way or will it cause a problem?

OK Now we are getting somewhere. Yes you should have tested with the lights ON. That is full load.

You can see that the system is capable of providing 14.0 volts to the battery but only at low RPM. You are loosing voltage as RPM goes up. That is dirty connections between the R/R(+) and the BATTERY (+) and the R/R(-) and the Battery(-).

If you followed the 3 steps to health you should have improved your connections between R/R and battery:

1. + side
2. - grounds side

You said you measured 0.25V on the positive side, so figure if the R/R is regulating to 14.5 then you should see no more than 14.25V at the battery.
If teh groudn is alos loosing voltage figure another 0.25, then upo are down to 14.0V.

Since you are dropping at least 0.7V (14.0 at idle down to 13.3@5K RPM) then you know for sure that your connections are not clean. You need to chemically clean not only the connections but also the crimps to the wires. You cant get into the crimps with a brush., You need either Naval Jelly or DeOxit.

The minimum your charging system needs to produce is 10 amps. It only takes 0.025 ohms to create a 0.25V drop at that amperage level. You can NOT measure that (unless you have expensive equipment) with an ohm meter, the only way is to do a full load voltage test.

Clean the connections between the plus side going through the fuse box and the grounds on the - side and re do the Revised Phase A tests on both positive and negative sides.

Once you get through that if you really have low voltage drops and you still cant get above 14.25V at 5K RPM then we could look at the stotor. Until then focus on connections.

[amedeo69]

Hi,
I realize that I do dirty connection between the R/R(+) and the BATTERY (+). I measured the R/R(-) and the Battery(-) and the voltage at 5000rpm is under 0.25v. I don't know where to find the dirty connection in the + wire. The wire goes from the battery and R/R to the ignition, under the tank and all taped up. Don't know where to start. I put some cleaning component in the ignition switch and checked the contacts on that, and they seem ok.
I would have to do a complete wiring.

[posplayr]

First step is get a schematic for your bike ad look at it.
The plus wire usually runs from the batter over to the main 15amp fuse. That path can be direct through a bullet connector or there is a primary cable from batt+ to the solenoid and thenthat goes to the fuse box.

Once you get to the fuse box you have contacts on the blade type you are then good to go. If there is pigtail of wires coming out of the fusebox be assured those wires connect to somthing inside namely crimps . Those need to be gleaned.

Finally the red wire coming out of the fuse box goes into the harness and then imeges to becom your r/r +, there is a "t" in the harness as that wire also continues to the ignition switch. Last resort open enough of the harness to clean and solder that "t".