Voltage regulator bad?

[RenoHuskerDu]

Oh boy, am I glad I found David. I've got a load of parts on their way.

Today we did a lot of maintenance and put in a new battery. The old one died, but date stamp showed it joined this mortal coil in 2017. Hmmm

Voltage of the new battery is parked at 12.5 and it won't come up when the motor is running. Now, if the motor starts up just fine by using that big old alternator as a starter, then it seems highly unlikely that it would not be putting out power. Windings work both ways.

I wonder if my voltage regulator has gone South to Mexico. Does the club car carry-all 272 have a separate voltage regulator? I can't wait to get back and look at the PDF parts diagram that David sent me.

[RenoHuskerDu]

Well, thanks to David, I found that voltage regulator in the pdf parts catalog, so I know where to find it. Now I need to check that its connections are in good shape.

[RenoHuskerDu]

David gave me great advice about how to test the alternator. There a jump to ground you can do on top to see if the alternator is putting out charging voltage. My alternator is putting out up to 18v, so we know the voltage regulator is at fault. I caught this in time to add a regulator in with my parts order from David.

All is joy in Mudville tonight

[inmars]

I also have a question about faulty regulators. If I get 17 volts at the battery would that be a regulator or starter/generator problem? I’ve tried 3 new regulators with the same results.

[RenoHuskerDu]

Originally Posted by inmars

I also have a question about faulty regulators. If I get 17 volts at the battery would that be a regulator or starter/generator problem? I’ve tried 3 new regulators with the same results.

That is odd. The regulator's job is to reduce voltage from the 18 or so that the alternator puts out, such that it's just enough volts to charge the battery.

17v at the battery posts is too much for the battery's health, as well as for the components on your cart such as light bulbs. Have you also had to change batteries? I wonder if the alternator itself is killing the regulators. 3, you say, wow!

Is this also a Carryall 272?

[inmars]

This is a precedent golf cart and used as a spare work cart on a golf course. The battery is fairly new, replacement was due to age of last battery. Unless a wire has come loose or off somewhere I don’t know what else it could be.

[Fairtax4me]

The yellow wire coming from the starter generator is shorted to ground. Probably pinched against the frame somewhere.
Grounding the yellow wire allows full current through the field coil in the S/G which makes it fun at max voltage all the time. Bad for the battery and bad for the S/G.

[inmars]

Thanks for the suggestion. I started tracing the wires today and didn’t see anything, I’ll look more tomorrow.

[RenoHuskerDu]

Originally Posted by Fairtax4me

The yellow wire coming from the starter generator is shorted to ground. Probably pinched against the frame somewhere.
Grounding the yellow wire allows full current through the field coil in the S/G which makes it fun at max voltage all the time. Bad for the battery and bad for the S/G.

I think he's right. Try just disconnecting that wire from its post on top of the alternator. Put some electrical tape on it. If, after that, you have only about 12v at the battery when the motor is running, then that wire is probably grounded out somewhere. Or the VR has failed.

[mrlmd]

More than likely your battery may be bad or was not fully charged when you installed it. Put it on a charger and see what the voltage reads if and when you can bring it up to full charge. That should be 12.6-12.7 V a half hour after you remove it from the charger. Let it sit overnight and see what it is in the morning. If it doesn't hold that charge, charge it up again and get it load tested at any garage or battery place or auto store, they will do it for free (because they want to sell you another one). The battery may be new but that doesn't mean it's good.