2013 drive efi charging problem

[tailslid1]

I have a 2013 Yamaha drive efi cart. I thought my battery was getting bad. Sometimes while running the cart with headlights and radio playing, I could tell it didn't turn over as fast as normal while starting. So I decided to install a deep cycle marine battery.

Two weeks after the new battery was charged and installed, it died on the course. After some troubleshooting, I found that the generator is not charging the battery at all. I put a voltmeter on the battery. It read about 12.6 volts. I started the engine, revved it up, still 12.6 volts. It should spike around 14 or so.

I replaced the voltage regulator. The problem remains.

What should I check next? How do I test the generator?

Thanks.

Rick

[tailslid1]

See if the photos work this time.
Rick

[Dave in VA]

Any warranty left?

[tailslid1]

I don't believe so. We don't have a local dealer anymore anyway. I'd have to load it up and drive a couple hundred miles. Not worth the trouble. I didn't think it would be that hard to diagnose, but it appears as though I was wrong.

Rick

[smallblock450sl]

Hard to beleive the brushes would be worn on a 2013. Take the rubber brush covers off, brushes should be well out of the "slides". Take a picture of them. The red and green wires should read 5 ohms (there the charging part of the generator). Take a very close look at the black/green'red wires on the wire harness side coupler that plugs into the voltage regulator. I've had several that a wire broke off.

[tailslid1]

Resistance tests out exactly 5.1 ohms.

If I put it back in the cart and test those two wires for voltage, will that tell me if the generator is good?

As suspected, brushes look nearly new.

Rick

[tailslid1]

Anyone know how to troubleshoot a generator charging problem?

Thanks.

Rick

[Prowlerguy1]

Originally Posted by tailslid1

Anyone know how to troubleshoot a generator charging problem?

Thanks.

Rick

I take the connector off of my Voltage Regulator. There should be a Red/white wire there, a green wire there and a black wire there. Short the green wire to the black wire using a short piece of wire with the ends bared into the end of connector. This "tricks" the S/G into thinking the V/R is asking for the most power that it can make (full, max current through the generator excitation field coil).

Start the engine, then pull the positive cable off of the battery. If the generator is working the voltage on the positive battery cable should have 14-20Vdc on it. You might have to get the engine above idle. Put the cart in neutral if you can. Otherwise, have someone on the brakes.

Test it with the voltmeter red test lead on the thick red positive cable off of the battery (the one that comes from the main starter relay). The voltmeter negative black test lead should be on the negative post of the battery. (Put the test leads on the right places before you start the cart.)

If you get anything over 14Vdc, the S/G is working.

If not, tell us what you find and we can troubleshoot farther.

Regards,
Todd

[tailslid1]

Unplugged the VR and jumpered.

Started engine. As soon as I pull positive cable, the engine dies. I'm assuming this is because the generator isn't supplying power to keep engine running?

Rick

[Prowlerguy1]

Originally Posted by tailslid1

Unplugged the VR and jumpered.

Started engine. As soon as I pull positive cable, the engine dies. I'm assuming this is because the generator isn't supplying power to keep engine running?

Rick

Yup!

With the V/R unplugged and the key on and the pedal pressed, is there 12V on the green wire?