Alternator Light

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May 19, 2013 | 09:18 PM

fast andy

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Alternator Light

I have a 1995 F150 Alternator/battery light stays on though gauge shows it is charging and I have never had trouble with battery. Please advise

May 19, 2013 | 09:54 PM

Stewart_H

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From: Central Coast of CA

Moved to the forum that addresses your year truck.

Stewart

May 20, 2013 | 09:49 AM

subford

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Joined: Aug 2005

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From: Easton,Ks

You need to check the voltage at the battery with the engine not running and again with it running.
Post back with what you read with a volt/ohm meter.

May 20, 2013 | 07:32 PM

Nothing Special

Lead Driver

Joined: Feb 2013

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From: Roseville, MN

I had the same symptoms with my 2002 F-350 diesel. On my truck if I recall the engine-off battery voltage was between 12-13 (good) and with the engine running it was 13-13.5 (kind of low). I thought it might just be a voltage regulator issue and I might be able to go a long time like that. It ended up being about 2 years. Then I got stranded with totally dead batteries.

That was a different truck, quite a bit newer. But it gives one possibility

May 22, 2013 | 10:46 PM

fast andy

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Do you think I can diagnose problem with a code reader?

May 23, 2013 | 01:59 PM

rla2005

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From: Kentucky

Quote:

Originally Posted by fast andy

Do you think I can diagnose problem with a code reader?

No, you need a voltmeter.

May 23, 2013 | 04:13 PM

Encho

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Joined: Dec 2004

Posts: 6,902

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From: Caracas, Venezuela

How long has it been since the brushes in the alternator were replaced? It's an easy procedure that cost about $10 if you buy them together and mounted on the plastic piece.

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May 23, 2013 | 06:59 PM

rla2005

Fleet Owner

Joined: Oct 2005

Posts: 20,784

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From: Kentucky

Quote:

Originally Posted by fast andy

Sorry.I,m new at this. Do I just put volt meter on battery.? First with truck not running then with it running?
I don't know about brushes in alternator as I purchased vehicle used about a month ag. Battery is a year or so old

You are correct sir! Take a reading with the engine off, then with the engine running. The running voltage should be in the 13.5 - 14.5 VDC range. Perhaps a little higher.

I have been a little remiss..Welcome to FTE!