Alternator question

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Dec 2, 2017 | 01:14 PM

kupiec20

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Fleet Mechanic

Joined: Nov 2007

Posts: 1,263

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From: DARTMOUTH MA

Alternator question

so driving home the other day. And the batt light started to flicker. Volts were low.
went home changed the alternator. Started it up without any issues.
So driving to work half hour into my trip and the voltaged jumped sky high.
light was back on for the volts being to high.
the volts would be normal at idle but as soon as the rmps increase the volts jump way up.
any thoughts?
thx

Dec 2, 2017 | 02:06 PM

Hussler

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Joined: Sep 2007

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From: Medford Oregon

How old are the batteries?

Dec 4, 2017 | 05:43 AM

kupiec20

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Fleet Mechanic

Joined: Nov 2007

Posts: 1,263

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From: DARTMOUTH MA

Quote:

Originally Posted by Hussler

How old are the batteries?

batts are fine. just don't understand why the voltage goes from 10v to 18v while driving.
Is there a regulator?

Dec 4, 2017 | 06:31 AM

DIYMechanic

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Joined: Dec 2010

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From: Orrville, Ohio

Yeah, there is a voltage regulator, it's built into the alt.

Dec 4, 2017 | 07:39 AM

kupiec20

Thread Starter

Fleet Mechanic

Joined: Nov 2007

Posts: 1,263

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From: DARTMOUTH MA

Quote:

Originally Posted by DIYMechanic

Yeah, there is a voltage regulator, it's built into the alt.

thanks.
ill have to swap it out with another new one.

Dec 4, 2017 | 08:02 AM

DIYMechanic

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From: Orrville, Ohio

That would be my recommendation. Also make sure that the single wire connection on the top of the alt is good and tight. The connector tends to loosen up and can cause battery light / charging issues.