Help with 2 stroke S/G tests?

[scottyb]

What is the sequence to test the output on a S/G on a 2 stroke G3?

Is there a wire to ground to see the generator put out full charge? Like the ezgo?

This little car sat and the mice chewed some wires I think I fixed them all and have fresh fuel and filters, plug, but the voltmeter says the new battery is dropping in voltage when the cart runs.

Thank you in Advance.

[DOOmsman]

Dog man I don't know of a test and can't see how
one could be done other than those dreaded words
replace with known good one. some one else may know of a test.

http://www.cunninghamgolfcar.com/dow...maha%20G9A.pdf

[bigstik40]

Here's an explanation covering the G2 S/G. I think the G3 will be similar.

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The R/W and grn wires go to the generator field. The voltage regulator applies power to this field (R/W & GRN)to cause the generator to "generate" and charge the battery. The way this happens is as follows:1. R/W wire is connected to Battery plus through the key sw. & foot sw.( both must be closed for this to happen). 2. Grn wire connects to the voltage regulator and, when working properly, the voltage regulator connects this GRNwire to gnd (bat. neg.) which results in current to the generator field. This connection to ground is pulsed on & off by the voltage regulator to cause the generator output to be 14.5 to 15.5 volts (measured across the battery). The R/W wire voltage should be the full battery voltage measured with respect to gnd. (bat -). The GRN wire voltage will be the pulsed voltage as mentioned above in 2. You should be making these checks with all the wires connected. You should be able to check the generator output pretty easily by connecting a voltmeter directly across the battery, then run the cart in neutral or with rear wheels lifted. Normal condition will be a voltage reading of 14.5-15.5 v. after running for a min. or so. If only reading battery voltage of 12.3 v. or so, you need to check if generator is functioning by applying full field current. This is done by connecting the GRN wire to ground (bat.-) with the cart running, and measure the battery voltage. The voltage reading should be high, in the neighborhood of 16-17 v. Only do this for a short time because of the high field current involved. If you do in fact get this high voltage reading, your generator is OK and the voltage regulator is probably bad. That about covers it !! - Hope this helps - be happy to answer any other questions to help you find your problem. - RAY

[scottyb]

Ray that is what we do on the Ezgo and the green wire is right on top of the S/G where is it on the Yamaha? I see a green wire at the V regulator?

[scottyb]

Ah HA!
My search for the green wire has netted a green and red/wht wire chewed off by a rat...
Searched the nearby harnesses and found where they should go! Somebody's G3 lives to run another day!

This forum really does work! Thanks for your help! Scottyb

[bigstik40]

Good deal, Scotty !!! Glad you sorted it out. Looks like Yamaha's can also use the same S/G test. - RAY

[scottyb]

That makes sense an S/G is an S/G, right?
I ain't afraid of no Yamaha
Battery voltage went up as high as 15v on my little test drive then settled right back down around 13-12 so it looks like the VR is working too

[crash12888]

Helps me with mine also, wasn't sure about both wires.
Thanks Guys.

[scottyb]

The green wire come off the engine side of the S/G and conveniently unplugs about 5-6 inches from the unit so a jumper with alligator clips would be alls ya need to test yourn.

[smallblock450sl]

I'm late to the party, but when checking all Yamaha s/g charging coil's you should read 5 ohms on the red/green output leads. Charging voltage out put should be 14.5 to 15.5 with the engine reving, it souldn't drop much below that, or it is not charging anymore, just running off the battery. Yamaha voltage regulators, up to G9's were adjustable (if they are stock Hitachie's). I Hate Rats..Nasty creatures!