G9 charging the battery

[redblaze45]

Hello. I have a G9 according to the wiring diagram. The tag says JG5 but the diagram for the G9 is actually what this Yamaha gas cart has. It was brought to me after having numerous parts changed out and still wouldn't charge. I have polarized the starter/generator. I get nothing from the starter/generator until I ground the green wire from it going up to the regulator. At which time I have anywhere from 13+- 18 volts at the battery depending on the rpm of the engine. With or without the regulator plugged in. I have went over every part of the wiring and checked what I know how. Does anyone have detailed ideas of what I may be missing? Like I said I have the wiring diagram that I have traced each wire. Any detailed help is very much appreciated!

[meimk]

What you are doing when you ground that green wire is by-pass the voltage regulator. Replace the voltage regulator and all should be good.

[redblaze45]

Shouldn't I be getting higher voltage (13-17 v) without having to ground the green wire? Without the ground I supply from the battery ground it shows nothing but battery voltage. Thank you for your help!

[redblaze45]

Does anyone have the part number and a good site to buy an oem voltage regulator for this cart?

[cgtech]

Originally Posted by redblaze45

Shouldn't I be getting higher voltage (13-17 v) without having to ground the green wire? Without the ground I supply from the battery ground it shows nothing but battery voltage. Thank you for your help!

Yeah, if the regulator was functional.

Part number is JF2-81910-11-00

[sformal]

When I had to replace my Voltage regulator, I wanted to switch to the old adjustable hitachi I finally found (the aftermarket are not adjustable). After 4 years, it now reacts too slowly...

I think the oem electronic regulator is keeping a too high voltage (15/15.5) for my use, but I understand why Yamaha is doing it as such.

So I decided to make one with an Arduino Nano with a Bluetooth connection to be able to monitor while on way and easily adjust it.

[redblaze45]

Wow! That sounds good. Very technical for me but as long as it suites the need. I just want to know that when I am finished with this cart that I have it done correctly. Not too little or too much. As soon as i get the new regulator I will post back.Thanks!

[cgtech]

Originally Posted by sformal

When I had to replace my Voltage regulator, I wanted to switch to the old adjustable hitachi I finally found (the aftermarket are not adjustable). After 4 years, it now reacts too slowly...

I think the oem electronic regulator is keeping a too high voltage (15/15.5) for my use, but I understand why Yamaha is doing it as such.

So I decided to make one with an Arduino Nano with a Bluetooth connection to be able to monitor while on way and easily adjust it.

That's wild! I know just what you describe, and that's awesome! Would you be willing to share the Arduino stuff you made with the world? You have done some really slick stuff over the years, and I appreciate your input to the forum!

[redblaze45]

I got the voltage regulator yesterday. I put it on last night and wide open it is putting out 16.3 volts which is less than the 18+ volts before. Thanks for the help with this. If the battery goes dead on my customer what is the easiest way for him to try to polarize the starter/generator?

[meimk]

I don't think I'd worry about it. Yamahas do tend to charge around 16 volts. Some accessories have trouble with it (like sound systems & power inverters), but that's the way they're made. I have had to "customize" an old style adjustable regulator for a customer on occasion.