intermitent battery light

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Aug 7, 2011 | 04:15 PM

mikren

Thread Starter

Mountain Pass

Joined: Apr 2007

Posts: 184

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From: Ontario

intermitent battery light

hey guys, my wife has been using the truck the last 2 days and said the battery light in dash has come on a few times then has gone out...also mentioned the radio display went out also...then back on ,is the a sign the alternator is dying ?

She said the truck still ran fine when the battery light came on....the battery light was not on for long. It did it a few times.

I checked the voltage on the batt while the truck is both running and not and it's good

Aug 7, 2011 | 05:10 PM

Dave G.

Elder User

Joined: Mar 2010

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Most likely cause is a failing alternator. The Amp gauge should also show a steady drop the longer you drive, or with a lot of things turned on, like lights, radio, wipers, etc..

Somewhat possible that the serpentine belt is slipping and not allowing the alternator to maintain constant speed. Should also check the battery cable connections to make sure that it can even take a charge.

Dave

Aug 7, 2011 | 09:38 PM

Bluegrass 7

Lead Driver

Joined: Sep 2006

Posts: 7,907

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If the Alternator is old it may be on the edge for brush wear.
Check the Alternator plug for being seated.
Battery cables etc
You won't see any voltage problem when measuring if the charge lamp is not on.
Normally if the Alternator stops charging the battery will still run everything until it's charge runs to low for some items such as the radio especially at night with the lights on.
With a single belt driving everything it seldom is the problem or you would have power steering and A/C issues with it and hear noises.
Good luck.

Aug 8, 2011 | 06:46 AM

mikren

Thread Starter

Mountain Pass

Joined: Apr 2007

Posts: 184

Likes: 8

From: Ontario

yeah I am suspecting the alternator also, it is old, but is there not a way to test and see if it is infact the problem ? like disconnecting the positive off the batt while the truck is running ?

Aug 8, 2011 | 10:42 AM

Bluegrass 7

Lead Driver

Joined: Sep 2006

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No no, don't do that on modern computer controled systems.
Take it to a store or shop to test on equipment.

Aug 10, 2011 | 12:05 PM

mikren

Thread Starter

Mountain Pass

Joined: Apr 2007

Posts: 184

Likes: 8

From: Ontario

ok, fired up the truck last night and batt light was on. I did a load test it defenitly is the alt. My question is.... 95 or 130 amp. I don't know which one I have at the moment, no markings on it. It's a 5.4L XLT, power doors,locks andwindows,a/c...no power seats or anyting else. Will a 95amp do the job as I can get one pretty cheap. Thanks again guys

Aug 10, 2011 | 01:10 PM

Bluegrass 7

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Joined: Sep 2006

Posts: 7,907

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Here are considerations for chooseing one or the other.
1. The power options you have such as A/C.
2. Winter temps you encounter.
3. Cold weather cranking and battery recharge time.
I would opt for the larger and the biggest battery capacity you can get for your worst case conditions even though it's summer now it will serve you well in winter.
Good luck.