What are some causes for this?

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Mar 6, 2007 | 09:59 AM

Broncobudy

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What are some causes for this?

OK, I will try this again in a different format...what are some of the reasons that my battery warning light in the instrumentation cluster is lit? Are there other reasons besides the alternator not working? Any chance there is a short somewhere? Where?

An aside, I have driven the Bronco for a while and all seems to be fine. Drove it last night with lights and radio on and zero notice that the battery is being drained. Drove it to work this morning. This makes me think there is a short in the warning light and not something wrong with the charging system.

Mar 6, 2007 | 11:02 AM

thelonerangerxlt

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BroncoBuddy, the first step is to take a voltage reading off the battery terminals with the engine idleing. This will confirm the alternator is working. Should read about 13.5-14v at idle.

Is this a 96? You might have a temp sensor under the battery that's gone bad.....

Do you also have an ammeter in the gauge panel, or only a warning light?

Mar 6, 2007 | 11:11 AM

rdz

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From: saskatoon,sask

i found the quickest way to find if your alt is good or not is have your truck running and pull off the positive cable if it stalls the alt is no good.

Mar 6, 2007 | 11:28 AM

Kemicalburns

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From: Bend,OR

dont pull the battery cable while the engine is running. especially for our newer efi rigs , the alts are internaly regulated and with battery unplugged it will send a spike thru the system.

Mar 6, 2007 | 11:32 AM

rdz

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From: saskatoon,sask

good to know ,i,ve only used it on older vehicles

Mar 6, 2007 | 11:38 AM

Broncobudy

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Quote:

Originally Posted by thelonerangerxlt

I do have an ammeter and it shows nice steady charging closer to 18 amps(I believe).

I also did some testing with some home equipment. I have a nice battery charger that can test the alternator. All I get though is a green light if ok and I tested it both at idle and with as much electronics turned on and it still gave me a green light.

I will get a voltage reading. My Bronco is a '95 w/351.

Mar 6, 2007 | 07:03 PM

ag30265

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From: Coweta,GA, GO DAWGS!!!!!!

If your voltmeter is correct, that might be the problem- not a lack of voltage but too much, the regulator in the alt could be bad and allowing excessive voltage out. During the warmer months if your alt. is overcharging it will cause the batt. to swell and depending on the length of the drive an overcharged batt. will act like a bad batt.