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Topic Review (Newest First)
10-03-2013 03:21 PM
gfiber As jerry said, likely lead oxide build up on the positive battery post. Grab a battery brush, remove both cables and do both battery posts and cable terminals. Over the years have seen a lot of this, people pull in for gas and when they try to start the vehicle you would get just clicks. If your headlights operate with out the key, turn them on and try to start the vehicle, if they go out immediately it's almost a sure bet the posts are dirty even if they do not look to be. Another battery test is if you can remove the cell caps, have some one try starting the vehicle while you look into the cells with a flashlight. If you see one that appears to be boiling, it's a shorted cell and the battery is bad. Remember charging voltage is generally between 13.8 to 14.2 volts DC, check it with a voltmeter when the engine is running placing the meter onto the battery terminals, if it meets this spec generally you can assume the alternator is likely ok, though this test does nothing to prove the alternator is capable of generating the current required to pick up the vehicle electrical load and recharge the battery.
10-03-2013 02:06 PM
jeff_in_rc Did you clean EVERYTHING battery cable related?? If not do yourself a favor and do it or you could run into the same problem again. Pay attention to the ground cable going to the block, the one on my YJ was finger tight!
10-03-2013 01:57 PM
SpartanX13X There was a lot of corrosion, I just cleaned it up and she roared! Thanks for all the help
10-03-2013 01:54 PM
BigDeaner Yup, sounds like a bad battery. I was having very similar issues and thanks to this forum, I chased down the problem. My "new" battery was junk. A new "new" battery and problem solved. Good luck.
10-03-2013 01:54 PM
Shelby427 Pretty simple as most have pointed out, you've eliminated the starter and using the jump battery, so it's got to be either the stock battery and/or cables and connections.

A battery that proves good under a load test isn't going to do you diddly if the cables and connections aren't any good, and visa versa.
10-03-2013 01:17 PM
Dextreme If you work for an autoparts store, simply try a different battery. I have had 12v batteries that said they were good and fully charged but the reality was that they were shot.
10-03-2013 11:06 AM
SpartanX13X I'll have to do it after class, thanks for all the help, hopefully they are just corroded
10-03-2013 11:02 AM
Jerry Bransford Your symptoms don't point to a bad alternator, they point to either a bad battery connection(s) or a bad/dead battery.

Stop wasting time, go remove, clean, & tighten both battery connections as described above before doing anything else. Cleaning the connections while the connector are still attached to the battery woudl be like trying to brush your teeth through your closed lips.

Edit: If getting the battery connections clean & on the battery posts tightly enough doesn't fix the problem, whoever tested the battery didn't know what they are doing (or the battery needs to be charged overnight). Performing a "load test" on a bad battery improperly won't always show it to be bad.

That the problem has to be from a bad battery connection or bad battery is confirmed by the fact that the engine starts ok with a jump battery clamped onto the outside of the battery connections.
10-03-2013 10:59 AM
SpartanX13X wouldn't it not run if I didn't have an alternator?, but I also had the battery fully charged and it still wouldn't go
10-03-2013 10:58 AM
Jerry Bransford First, letting an engine run 20 minutes doesn't even come close to charging a battery that is low or dead.

What I would do first is completely remove both battery connections. Use a wire battery brush that is for sale in your auto parts store & THOROUGHLY brush the battery connectors, the inside of them where they touch the battery posts especially, and the battery posts themselves.

Then reattach them tightly enough that neither connector can be moved when you try to with your hands.
10-03-2013 10:56 AM
Relocatedduckman Have you tested the alternator??
10-03-2013 10:54 AM
SpartanX13X also I did let it run for 20 minutes then tried to start it but it wouldn't start
10-03-2013 10:52 AM
jeff_in_rc If the ends are corroded really badly replace, if the ends that clamp to the battery are all messed up replace, you can use your eyes to tell, this is the easy part.
10-03-2013 10:49 AM
SpartanX13X battery is good, I did test it (I work for an autoparts store) and it was running this morning after I replaced the starter, it just needs to be jumped everytime, and then I run into the idleing problem. it was running fine Monday, then Tuesday the problems started, didn't have a chance to look at it until last night, also how would I know if a cable was bad, I don't really know electrical
10-03-2013 10:45 AM
Jerry Bransford If it starts ok with a jump battery, there are only two possible sources of that problem... your battery isn't really good (or charged well enough) or the connections at the battery are simply bad, loose, or corroded.
10-03-2013 10:44 AM
Finazzo007 Probably getting bad ground. As Jeff said check each connection and make sure they're good and clean.
10-03-2013 10:42 AM
sparky Your battery does not have enough charge.

Step by step.
Make sure battery and starter terminals are clean and tight.
Has the battery been loaded tested.
Have the alternator tested also.
10-03-2013 10:41 AM
jeff_in_rc Are you SURE the battery is good? Not being a butt, just asking, have you had it tested?

Next disconnect the battery and go thru EVERY battery cable connection you can find, clean and make sure they are all tight. Replace any cable you think is bad and see what happens.

Let us know what you find.
10-03-2013 10:31 AM
wont start without jump battery is good, starter is new

I went to start it and it wouldn't, turns out my starter was bad, so I replaced it this morning, now it needs to be jumped for it to start (yes my battery is fine), also another problem is that sometimes when I get it to start it wont idle, or I need to give it gas for a few minutes for it to idle thanks for the help

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