Thanks to everyone, R/R, Shindengen 238-12

[Boondocks]

Please correct me if I'm wrong, but I thought the third wire from the stator was supposed to feed directly into the headlight. Maybe I have the totally wrong idea (or wrong bike model)?

This was the original wiring setup, with one stator wire going through the headlight switch (for a model that could turn the headlights off). If the headlight were off, the switch broke the connection from the stator wire to the R/R. This was presumably done to help prevent overheating the R/R by reducing the available unneeded charging capacity. If the headlight is on all of the time (as with most all U.S. models), the circuit is not switched. The circuit is redundant and can only result in a loss of efficiency due to voltage drop or a potential short.

Therefore, in the case of an always on headlight, it works just as well and probably better to eliminate this bypass loop to the headlight area and back to the R/R. The wires to the headlight and back are disconnected and the stator wire is connected directly to the R/R.

 

[Boondocks]

Re: S

Re: S

...I just wish I could hook the sense wire to something that I could use the third stator wire....

This isn't difficult. You should get an electrical multitester if you don't have one. You can use the fuse block if it's convenient. Pull one of the switched fuses (Lights, Signals, Ignition) and turn on the ignition key. Set the tester to an appropriate DC voltage range (over 12V). Put the red test lead on one side of the removed fuse connection and the black test lead to a good ground. If the circuit is hot (12+V), then you want to make your black wire connection to the other side of the fuse connection. That side will become hot when the fuse is replaced. Put the fuse back in and put the red test wire on either side of the fuse (black to ground) and toggle the ignition switch to verify that the voltage is present only when the ignition is switched on.

I don't know why you've had a problem with this sense wire connection so far unless you wired it after a switch such as the stop light switch. In this case the sense wire wouldn't be activated unless the stop light was on.

On the other hand, if you had connected the sense wire to a reliable "hot when ignition on" source, it's possible that the R/R is not functioning properly. It's worth trying again to verify your results.

How much over 15V are you getting at 5,000 RPM with the sense wire connected properly?

 

[flyingace]

Please correct me if I'm wrong, but I thought the third wire from the stator was supposed to feed directly into the headlight. Maybe I have the totally wrong idea (or wrong bike model)?

This was the original wiring setup, with one stator wire going through the headlight switch (for a model that could turn the headlights off). If the headlight were off, the switch broke the connection from the stator wire to the R/R. This was presumably done to help prevent overheating the R/R by reducing the available unneeded charging capacity. If the headlight is on all of the time (as with most all U.S. models), the circuit is not switched. The circuit is redundant and can only result in a loss of efficiency due to voltage drop or a potential short.

Therefore, in the case of an always on headlight, it works just as well and probably better to eliminate this bypass loop to the headlight area and back to the R/R. The wires to the headlight and back are disconnected and the stator wire is connected directly to the R/R.

I'm not sure about that. I've heard that if an always-on headllight burns out, the extra current from the third stator wire can fry the R/R. The headlight must be serving to reduce or eliminate the charging from the third wire. I wouldn't bypass the headlight until I knew for certain. Even with a switched headlight, the charging current is either off or going thru the headlight - never straight from the third wire to the R/R.

Other electrical experts please - Earl?

 

[Boondocks]

I'm not sure about that. I've heard that if an always-on headllight burns out, the extra current from the third stator wire can fry the R/R. The headlight must be serving to reduce or eliminate the charging from the third wire. I wouldn't bypass the headlight until I knew for certain. Even with a switched headlight, the charging current is either off or going thru the headlight - never straight from the third wire to the R/R.

Other electrical experts please - Earl?

Perhaps you've misunderstood my explanation. To expand it a bit more:

Yes, it seems the third wire was "dedicated" to the headlight on a switched headlight model.

Yes, if a headlight burns out more charging capacity would be available which would put an additional load on the R/R. It wouldn't necessarily fry it immediately, as usually you (or a cop) would notice that the headlight is burned out and it would be replaced.

No, with a switched headlight the charging current is not going through the headlight when it is turned on, but is directly connected to the R/R through a return wire. Remember, the stator charging current is high voltage (80+V @5,000 RPM) AC current, hardly appropriate for the headlight. :wink:

However, this circuit truly is redundant in an always on headlight system (at least like mine), since there is no headlight switch, only high-low and turn signal switches which can't switch the stator wire. The wiring diagram for my bike (and I assume that it is essentially the same for other GS models with always on lights) shows that the "headlight" stator wire is directly connected to the return wire which in turn is directly connected to the R/R. It is always connected even if the headlight is burned out. It would be my guess that Suzuki produced one wiring harness for models with switched and unswitched headlights. It seems instead of eliminating the headlight loop for "headlights always on" bikes they chose to leave the wires "as is" and simply connect them.

That's why it seems that this "headlight loop" circuit is superfluous on a "headlights always on" bike.

 

[Sandy]

Please correct me if I'm wrong, but I thought the third wire from the stator was supposed to feed directly into the headlight. Maybe I have the totally wrong idea (or wrong bike model)?

This was the original wiring setup, with one stator wire going through the headlight switch (for a model that could turn the headlights off). If the headlight were off, the switch broke the connection from the stator wire to the R/R. This was presumably done to help prevent overheating the R/R by reducing the available unneeded charging capacity. If the headlight is on all of the time (as with most all U.S. models), the circuit is not switched. The circuit is redundant and can only result in a loss of efficiency due to voltage drop or a potential short.

Therefore, in the case of an always on headlight, it works just as well and probably better to eliminate this bypass loop to the headlight area and back to the R/R. The wires to the headlight and back are disconnected and the stator wire is connected directly to the R/R.

I'm not sure about that. I've heard that if an always-on headllight burns out, the extra current from the third stator wire can fry the R/R. The headlight must be serving to reduce or eliminate the charging from the third wire. I wouldn't bypass the headlight until I knew for certain. Even with a switched headlight, the charging current is either off or going thru the headlight - never straight from the third wire to the R/R.

Other electrical experts please - Earl?

The power from the third wire does not actually go through the headlight. It is controlled by a separate set of contacts in the headlight switch. If the switch is on the AC from the stator goes directly to the R/R, if the switch is off that AC circuit is open and nothing goes to the R/R. Most GS's have the switch locked in the on position or are ridden with the headlights on all the time so the switch in this case is redundant and only another possible source of a bad contact. Bypassing the switch just eliminates this potential problem. If the headlight switch is on or the switch is bypassed makes no difference as the current does not actually flow through the headlight. Yes there will be some extra current to R/R with the headlight burned out but remember you still have the instrument and tail lights in that same circuit to provide some current draw.

EDIT. Ya beat me to it Boondocks ..........yeah what he said.

 

[flyingace]

The 'little light' finally went on. I had thought the third wire went directly thru the headlight via some kind of rectifier or something. Now I see that the point is to prevent all three stator wires from going thru the R/R without the headlight being on. And why in a non-switched light, you could fry the R/R since you can't turn the light switch off.

Thanks for helping me understand this.

Ace.