Battery Lite on Dash Concern

Topic: Battery Lite on Dash Concern

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Posted: 10/27/08 5:39am Message 11 of 18

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79FOREVER

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METAIRIE, LA - USA

Joined: 6/7/2007

Posts: 144

Vette(s): 1979 BLACK COUPE

Installed a new re-manufactured, 63 AMP. I checked the positive battery cables and connections via the troublshooting page that came w/ the alternator. It states that a reading higher than 0.35 voltes indicates a problem with the positive battery terminal to the alternator or fuse block connectors. If reading is higher than 0.75 volts look for blown fueses, swollen or discolored fusible links, or an open wire. I am getting 0.55 - 0.60. All checks done w/ lights and fan on, about 3000 RPM. Should I be concerned? All other volts checks are within guidance.

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Battery Lite on Dash Concern

Posted: 10/27/08 3:41pm Message 12 of 18

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acplus

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Canada

Joined: 6/23/2008

Posts: 558

Vette(s): 1972, 1980

Is the light still on?

John

Battery Lite on Dash Concern

Posted: 10/27/08 7:45pm Message 13 of 18

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kstyer

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CUYAHOGA FALLS, OH - USA

Joined: 12/2/2003

Posts: 6424

Vette(s): 1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!

If you are refering to connecting the meter leads to the positive bat term, and the pos alt term they you are just a bit high over 0.5 v. Up to that point is okay, but over is too much. If it is high, look for a resistance in the current path (wires and connections) between the battery and alternator.

On the flip side, if you still have good charging voltage at the battery and everything is working, you don't have enough of a problem to worry about.

Battery Lite on Dash Concern

Posted: 10/28/08 5:50am Message 14 of 18

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79FOREVER

Former Member

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METAIRIE, LA - USA

Joined: 6/7/2007

Posts: 144

Vette(s): 1979 BLACK COUPE

acplus,

Kstyer,

Yes doing that check.

It states that a reading higher than 0.35 voltes indicates a problem with the positive battery terminal to the alternator or fuse block connectors.

I am getting 0.55 - 0.60.

13.44 at battery. 14.42 w/o lights & fan on.

Battery Lite on Dash Concern

Posted: 10/28/08 4:08pm Message 15 of 18

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acplus

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Canada

Joined: 6/23/2008

Posts: 558

Vette(s): 1972, 1980

If you have a set of good booster cables long enough, carefully attach one end to the big red terminal on the alt and then to the positive terminal on the battery, now take a volt reading at the battery...any change? Then disconnect the booster cables and re-attach to the alt bracket or to the ground bolt on the alt, and the other end to the ground terminal on the battery, now take another reading....and change? This will help isolate if you are dealing with a positive wire feed problem or a ground, if there is no change maybe your alt can only put out 13.44 under load, When I replace alts I use the 100 amp, just in case other electrical equipment is added later. 13.44 volts is fine for a charge.

Did you check your battery volts with the tranny in gear?... I don't know if you have a Automatic tranny or not?

Hope this helps.

John

Battery Lite on Dash Concern

Posted: 10/28/08 4:25pm Message 16 of 18

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kstyer

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CUYAHOGA FALLS, OH - USA

Joined: 12/2/2003

Posts: 6424

Vette(s): 1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!

The 0.35 is also considering the drop from the alt case to the ground of the battery. Total circuit cannot exceed 0.5 for best operation. But the very small excess you have with the numbers you have at the battery will not cause you a problem or damage anything.

If you do want to improve the reading, check all the connections between the bat and alt. You can put one lead of your meter on each side of any connection and check for the voltage drop at that point. If you find over 0.1 at any connection, clean it and reduce the drop. Use dielectric grease on and connection to maintain the contact and prevent future corrosion and bad contacts. It takes time and effort, but is always a good thing. But again, with the numbers you have, it will function okay with no damage. Yes it could be better.