Battery light? Charging issue?
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 34
Likes: 0
From: Spring TX
Battery light? Charging issue?
The battery light on my dash lights up when I start the car but goes out after I rev the motor over 1500 RPMs. The battery does go dead after a few times of starting the car. I get about 4-5 starts out of one charge of the battery charger.
I have underdrive pulleys and I just had the alternator tested as good. Not quite sure if the battery is bad or not. I've had charging problems with the car since I got it (in 93). Any help would be appreciated.
I have underdrive pulleys and I just had the alternator tested as good. Not quite sure if the battery is bad or not. I've had charging problems with the car since I got it (in 93). Any help would be appreciated.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
I don't mean to be offensive, but underdrive pullys on a street car is stupid, it saves about 10hp max. So Autozone or whoever says the alternator is good, you have either a charging problem or a discharge issue or both. If you have a voltmeter, check the alternator output at idle and abobe 1000 rpm, it should be 13.5 or better. That is the big red wire on the back of the alternator. Run the same checks at the battery, this will tell you if the system is charging at all. Once thats sorted out, you need to determine if there is a discharge issue. Make a test light with a brake light bulb, disconnect the Pos battery cable and connect the test light between the battery post and the cable. With the doors closed, everything off, there should be no light. This is the first test, if the light lights up, you need to start pulling fuses until it goes away. Frequent failures are the interior light timer and the diode pack in the alternator. Do all that and see where you are.
Race Director
Joined: Nov 1999
Posts: 10,643
Likes: 8
From: Foxfield CO 1970 Convertible
I agree w/Sixfooter. Clearly, you're not getting any charging at idle. This also means you probably aren't getting sufficient charging when any accessories are on - radio, headlights, brake lights, fan, A/C, etc. You are borderline on charging and may be discharging the battery during a good portion of your drive time. If all your electronics appear good, first thing I'd do is get the regular pulleys back on. Secondly, you may have damaged your battery - it might only be getting a surface charge. If it's older than 5 years it could be time to replace it.
Good luck
Good luck
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 34
Likes: 0
From: Spring TX
No offense taken 6footer. The battery is a DieHard with I believe 800 CCA. I'll check things out with the meter and test light. Thanks for the help. I suppose I'll put those factory pulleys on too. The battery is over 5 years old and may be bad. More than likely from the same issue that keeps killing it.
Thanks for the help guys.
Thanks for the help guys.
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 34
Likes: 0
From: Spring TX
Not quite sure what you mean. There are about 5 wires coming out of the darn thing. One that has a boot on it. 2 that share the same terminal, and the one that has the plastic connector that plugs into the alternator.
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Well my battery light used to be on... Was the alternator. Was pretty impressed it lasted as long as it did, as those things are pretty common to fail. I just replaced it with one of those lifetime warranty kragen ones haha.
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Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Hoss, you have the correct type alternator. Batman is talking about an aftermarket alt some guys think is a good idea for some reason. It is called a 1 wire because you don't use the side connector you refer to. Never listen to anyone trying to tell you to use a 1 wire alt on a normal street car, they are meant for straight up street rods and farm equipment.
Drifting
Joined: Jul 2005
Posts: 1,891
Likes: 2
From: Baltimore MD
The one with the "BOOT" on it should be labled as "BAT" that's the one that leads back and charges the battery.
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
Hoss, you have the correct type alternator. Batman is talking about an aftermarket alt some guys think is a good idea for some reason. It is called a 1 wire because you don't use the side connector you refer to. Never listen to anyone trying to tell you to use a 1 wire alt on a normal street car, they are meant for straight up street rods and farm equipment.
