Battery Light On

[Rano]

I have a 1996 Ford Bronco XLT with Ultramount Western Plow and Isolation box. The battery light stays on on the dash. Voltmeter shows shows charging, confirmed 14.8 volts at battery when idling with meter. Battery new and altenator is 2 years old. Not sure what is going on.

 

[BroncoJoe19]

That doesn't make sense. Can you easily disconect the electricals to the plow? It seems to me that when things don't make sense, the problem is often in the aftermarket add-ons, like a user installed radio.

 

[AdamDude04]

I just ran into this the other day myself.. got a "new" alternator because mine was knocking (bearing going out)..

Anywho, this "new" alternator worked until I got about 15 miles from home. Then my battery light came on. You're not only suppost to test the connection when at idle, but also when reved up to about 2k rpm.

You should be able to stick the volt meter pin into the postive and negative conection on the battery, position the volt meter to where you can see it, and manualy move the throttle by hand at the throttle body to rev it up. If volts jump up, then there is your problem. Alternator or volt. regulator.

Easy/simple test. Good luck.

 

[BroncoJoe19]

sorry... was thinking of a different thread

 

[Rano]

Ran it a idle and 2k and voltage at battery stays a about 14.7. Also tried with plow diconnected and got same results.

 

[BroncoJoe19]

I wonder if 14.7 is too high, and if so could that turn on the light?

I think it is supposed to be 14.4

 

[BroncoJoe19]

Here is a diagram of the circuit, I don't think it is particularly helpful in this situation.

 

[AdamDude04]

I wonder if 14.7 is too high, and if so could that turn on the light?

I think it is supposed to be 14.4

I don't think so. Mine is around 12.4 after sitting for a day.. running it hangs around 16.2-16.7

Been like that for the last 3 years

 

[BroncoJoe19]

I don't think so. Mine is around 12.4 after sitting for a day.. running it hangs around 16.2-16.7

Been like that for the last 3 years

Adam,

I don't know how to respond to that. Well I guess over charging won't set the battery light, but charging at 16 volts could boil the water out of the battery, so I suggest that you keep an eye on your battery acid level, or one day she just won't crank.

 

[AdamDude04]

Adam,

I don't know how to respond to that. Well I guess over charging won't set the battery light, but charging at 16 volts could boil the water out of the battery, so I suggest that you keep an eye on your battery acid level, or one day she just won't crank.

Overcharging will set off the battery light. I found this out the other day with the "new" alternator the other day was overcharging. I not only heard it, but also saw the battery light, and the volt meter jump up to 17-17.5v range on the guage.

I don't forsee a problem with the battery charging at 16ish volts.. Battery has a sticker "june 2006"..So that's almost 4 years old..I've had the truck 3 years with no issues.

What I'm curious to know is the volt limit for these trucks. At what voltage does the battery light come on? 10volt (dying) and 17 volt? Anyone with info, please post up!

 

[Rano]

I got a chance to look at the wiring and found the fusiable link by the starter looks like it got very hot at one time. The previous owner had the altenator go bad two years ago and the link probably got hurt then. Also the small plug at the altenator is corroded and brittle. I think I will replace the fusable link and both plugs on the altenator to be safe. Do not know when I will get a chance to do it as I broke my hand and everything is a challange these days. Will post results after I change the items. Thanks for all the ideas.

 

[Seabronc]

Overcharging will set off the battery light. I found this out the other day with the "new" alternator the other day was overcharging. I not only heard it, but also saw the battery light, and the volt meter jump up to 17-17.5v range on the guage.

I don't forsee a problem with the battery charging at 16ish volts.. Battery has a sticker "june 2006"..So that's almost 4 years old..I've had the truck 3 years with no issues.

What I'm curious to know is the volt limit for these trucks. At what voltage does the battery light come on? 10volt (dying) and 17 volt? Anyone with info, please post up!

Other than the fact that your battery will heat up to the point it may explode. That is way too high and seems to indicate that the sense line is not connected properly. Since I don't remember what year or style of alternator you have I can't give you a place to check.

Good luck,

>-