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Discussion Starter #1
So my 68 mustang 5.0 is having some battery issues. Right now I put a volt meter on it and it shows 12.25 volt, I open the door and no lights come on I go to turn the key and nothing happens. I can jump start it with a jump battery starter but when i turn it off i don't have any power. So my question is is the battery dead? it's a 10 year old battery when I do jump start it the alternator is putting 14 volts when running.
 

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At 10 years I'd suspect the battery. I just replaced my 10 year old battery. It would start the car on the first or second try if it had been on the float charger, but if you needed a third try you were out of luck.

Alternatively, check all of your connections. A poor connection will cause all kinds of problems. Check the grounds and check the cables themselves.
 

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At 12.25volts the interior lights should be coming on as they take very little current to work. So, i'd be looking into that a little further.
I agree with the above comments..10 years on a battery means basically that it's on borrowed time and yes by all means check all your connections to ensure they are clean and tight. Grounds are important!

I'd put that battery on a charger and charge it fully. Then pull the headlights on high for a minute or so just to remove the 'surface charge', then i'd do a load test on the battery.
I think you will find that it won't pass the load test.

I usually disconnect the battery for the above test. It assures that it isn't powering up anything in the car while being tested.

......John
 

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Discussion Starter #6
Thanks I have been suspecting it could be a grounding issue, when I get a chance this weekend I will put the battery to charge and check my connections to the battery.
 

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When you check the ground, check both ends. Remove it from the engine block, clean and reattach. Also, remove the engine to body ground, clean both ends, and reattach. Usually this second ground is on the back of the engine connected to the firewall.
 

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Remove the cables at the battery. Make the posts and the insides of the terminal ends shine. Replace the cables and tighten securely. See if that fixes your issue.
 

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It wouldn't hurt to take the battery to your local auto parts store and have them do a load check, then you would know if the battery is good, dying or dead.....
 

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Saturday I will take the battery to the parts store and get some new cables.
Insure the battery is charged to capacity and request they do a "load" test.
Good Luck...
 

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After checking the grounds, I would suggest you buy the biggest battery that will fit in the tray without interfering with hood closure, tiedowns, or cable reach. Also, might be a good time to replace cables with heaviest gauge you can find. And check the electrolyte level occasionally, I've seen many a weak battery that had levels below the full level. Liquid should look cupped, not flat when looking straight down the fill opening. Always good to cover the basics.
 

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Discussion Starter #15
Took the battery to get charged at autozone to get charged they said it's at 60% charge capacity so it's on its last leg.
 

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FYI, not only should you have a ground to the block, but, aground to the chassis from the the block. I would suggest, if one is not present, a "ribbon" style cable fro the head to the chassis. When it come s to "flow" ribbon grounds are better, due mostly, to the surface area. However, if not readily available, then, go with a HD able from the rear of the head to the chassis.
many of our instruments and the horns too, rely on a good ground.
Yeah, 10 years is a stretch!
 
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