Alternator High Charge

Kelly MT · Dec 21, 2008

The charge on my Versatile 150 Series II is indicating a charge of 15+ volts. It has a Delco alternator on it. What would cause this condition. Thanks for any help,PK.

Anonymous-0 · Dec 21, 2008

Bad voltage regulator. If it runs this way for more than a few minutes after starting the engine, this needs to be fixed or it will boil the acid out of your batteries and onto your tractor's metal parts. BTDT.

Kentb of SWMO · Dec 21, 2008

Could be a bad regulator or if the alternator is a internal regulator unit, a wiring problem. If an internal regulated Delco with three terminals, use a volt meter and check the voltage on the terminals. With the ignition switch OFF you should have 12 volt on the battery terminal, Zero volts on the next terminal to the right and 12 volts on the terminal to the right of it. Turn the ignition switch ON you should have 12 volts on all three terminals. If this is ok, change the alternator. If this is not ok you have a wiring problem/

Kent

El Toro · Dec 21, 2008

It may be the regulator. Your local shop that rebuilds alternators and generators can test it for you if it has an internal regulator. How much above 15 volts is it showing? Do you need to add water to the battery very often? Hal

MarkB_MI · Dec 21, 2008

Are you sure your voltmeter is correct?

The voltage regulator is set up to put out more voltage in cold temperatures. 15 volts may be normal, depending on how cold it is where you are.

RodinNS · Dec 21, 2008

I wouldn't get too excited about it IF it's under 15.5V and you're sure that the meter is correct.
Are you working with some old analogue meter or a good digital Fluke.... or some cheap china type thing? I wouldn't hold the latter to much more than 1/2 a volt in accuracy.

Again, some regulators are temperature compensated to some degree, so 15 V is not abnormal in this kind of weather. If this was July, and 90 degrees, then I'd say you have a problem.

Rod

Kelly MT · Dec 21, 2008

It has been been below zero this last week. The voltage is indicated on the tractor volt meter, good quality factory meter. I'll do the checks recommended tomorrow and let you know what I see. Thanks for all the help. PK

Bob · Dec 21, 2008

The terminal marked #2 on the alternator is "voltage sense". It may be jumpered over to the alternator's large output stud or run to a point more it's more near the battery to more accurately sense actual battery voltage.

If the wire to that terminal is not making good contact or is disconnected or broken, the alternator will default to charging about the voltage you are seeing... a Volt or two too high.

BEFORE condemning the internal regulator, check with a test light to see if there's battery voltage to the #2 terminal with the engine "OFF", then "ON". If there's battery voltage at the connector, be SURE the terminal is clean so it makes good contact. The regulator terminal is STEEL, and typically rusts, making for a poor contact.

El Toro · Dec 22, 2008

I had a 1972 Ford with the 429cid engine and the charging voltage on it was 15.25 volts. The shop manual called for that too. Never had to add water and I ran it south down the Interstates in the heat and never had any problems. Hal

Alternator High Charge

Kelly MT

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Anonymous-0

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Kentb of SWMO

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El Toro

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MarkB_MI

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RodinNS

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Kelly MT

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Bob

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El Toro

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