My engine won't start when I try to jump it

MR.POLAR

MEMBER
2008 FORD F-150
120,000 MILES

Hi, I havent driven my 2008 ford f150 in a few weeks because the air conditioner started to go out and eventually did. Two days ago I noticed that the battery was completely dead and the key less entry would not even work but when I tried to jump start it everything worked fine and it was able to start no problem but the a/c was still not functional. I tried starting it today and it did not start so I put gas in it a few hours later and tried to start it again and this time the engine did not even try to turn over, my question is do I need to let it charge longer than just a minute or is it a problem with the battery all together? It has been sitting outside everyday and it was hot when I tried it the second time.

Wednesday, May 2nd, 2012 AT 7:40 PM

4 Replies

CARADIODOC

MECHANIC
34,185 POSTS

You charged it for a minute? It will take a good 15 to 20 minutes just for the electrolyte to become conductive to where the battery will start to take a charge. If your charger has an ammeter, you will see the current start out near 0 amps, then slowly begin to increase to around 10 - 15 amps. Don't let it go over that if it's a five-year-old battery. Charge it for at least an hour on the lowest rate. When it comes down to five amps or less, you can consider it fully-charged.

You should only use the lowest setting when using a charger.

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Wednesday, May 2nd, 2012 AT 8:25 PM

MR.POLAR

MEMBER
1 POST

What if I can only use another car to jump start it?

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Friday, May 4th, 2012 AT 1:05 AM

CJ MEDEVAC

MECHANIC
11,005 POSTS

SEE AND REALLY DO THE STUFF IN MY LINK.....MAINLY THE STUFF HALFWAY DOWN

http://www.2carpros.com/questions/1996-chevrolet-tahoe-wont-start-sounds-dead-battery-jumpbox-get-same-reults

THE PIC I HAVE AT THE BOTTOM OF THE LINK IS A 1985 JEEP CJ 7 THAT WOULD CLICK ONLY, BUT IT WOULD JUMP FROM ANOTHER VEHICLE, AS IF NOTHING WAS WRONG.......SINCE THE BATTERY WAS BRAND NEW, THE OWNER SWORE IT HAD TO BE SOMETHING REALLY SERIOUS!

KEEP US POSTED ON YOUR PROGRESS

THE MEDIC

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Friday, May 4th, 2012 AT 2:50 AM

CARADIODOC

MECHANIC
34,185 POSTS

Yup, a jump-start will do the trick but it will take a while if the battery was totally dead. Normally when the battery is just too low to crank the engine, it's not totally dead, and will begin to charge right away. In that case you can get a jump-start and go driving, but it will take a good 10 - 15 minutes to charge the battery enough for cranking again. It could take over an hour of driving to fully charge the battery.

It's when the battery was completely dead that it takes at least 15 minutes on a charger or with a jump-start before it even starts to charge up. You may be able to drive the car right after the jump-start but it likely will not crank again unless you drive it half an hour or so.

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Friday, May 4th, 2012 AT 3:36 AM