Red R/R Wire

[Hokano12]

Hey guys,
Was doing some tests on my gs425 stator/R/R today and noticed the red wire coming from from the R/R led into the harness then I lost it after that. Did some research and found that some people just connect that red R/R wire directly to the battery with an 15amp inline fuse and they noticed a good change in voltage/charging. I did a couple of the quick tests and at 2500rpm I was getting about 12.6v and at 5000 I was getting 12.8v. Would running this inline fuse straight to the battery make any difference with charging or would I just have to replace the stator?

[Steve]

I have not examined the wiring on a 425, but I don't think it would be much different than any other GS.

One the larger GSes, the overall wiring goes like this:
Power flows from the battery, through the MAIN fuse, to the ignition switch, back to the rest of the fuses, then to the individual components. The red wire joins between the MAIN fuse and the ignition switch. Wired like that, when you turn the bike ON, then hit the starter button, the bike is running on the only source of power available, the battery. Once the engine is running and the stator is turning, the output of the R/R will start to provide more than the battery. As the R/R output increases, it will provide everything the bike needs, then the excess goes the other way from the joint to charge the battery.

In that wiring diagram, the 15 amp MAIN fuse powers the bike before the R/R takes over. The bike requires about 10 amps, so that's not a problem. When the R/R takes over, It might put out up to about 20 amps. 10 will go to power the bike the rest will go back through the MAIN fuse to charge the battery. If you move the connection point, you may overload the MAIN fuse. Putting in a larger fuse will overload the wiring. Please keep the wiring stock, unless you change the harness to include properly-sized wires.

.

[Hokano12]

Ok, I believe there is only 1 main fuse on the gs425. Did the no load alternator test per the owners manual and each test indicated 70 volts AC (satisfactory for the gs425). Looks like I will be upgrading to an sh775 r/r soon here. I will keep the stock wiring configuration. Thanks for the reply Steve!

[Brendan W]

Hey guys,
Was doing some tests on my gs425 stator/R/R today and noticed the red wire coming from from the R/R led into the harness then I lost it after that. Did some research and found that some people just connect that red R/R wire directly to the battery with an 15amp inline fuse and they noticed a good change in voltage/charging. I did a couple of the quick tests and at 2500rpm I was getting about 12.6v and at 5000 I was getting 12.8v. Would running this inline fuse straight to the battery make any difference with charging or would I just have to replace the stator?

Are those voltages at the battery terminals? Have you checked the drop between the r/r negative and the battery negative and similarly on the positive side. Ideally these line drops should be of the order of 0.1 Volt.

[Hokano12]

Yes I did that test and ran engine at 5000rpm and saw it was less than .25v