Why wont my car crank over?

by **SIXSEATER** » May 12th, 2011, 6:32 pm

Hi guys,

Have recently noticed that my car wont start when trying to crank over...

I find this strange as i replaced my battery about 2 months ago.

My initial thoughts were either a faulty new battery or a rooted alternator.

So, out comes the multimeter and did a few testings....

With the car running the alternator showed a reading off 14.0 Volts, this was with all electrical components (Heater, Stereo with 2 Amps and 12inch Sub, Headlights, Wipers) all switched on. At the same time I checked the battery which was showing about 14.2Volts so there wasnt much difference..

A few ppl have said to try disconnecting the Battery positive terminal while the car's running and if the car switches off on its own then its a faulty Alternator but mine seemed fine.

After jump starting my car with my other BA the car was running fine, actually took it for a spin and all was well but as soon as i switched it off after 15mins of driving than there was a no go? So i go and check the battery with my mutimeter and the volts suddendly dropped to about 11.2volts? I then change batteries with my other BA as i thought maybe it was rooted but i had the same issue with that connected as it still wouldnt crank over....(and showing roughly same volts 11.4)

Im not a pro but it seems with some of the testing done that the alternator and battery are working fine as they're both showing 14+ volts while the cars running so im kinda puzzled what the issue could be as ive checked for loose connections and all seem to be intact....

btw cars a ba xr6t
Any advise would greatly be appreciated.

cheers

by **SIXSEATER** » May 12th, 2011, 7:33 pm

Just checked the battery with the multimeter and its dropped to 11.2v now? hmmm interesting!

by **Customxg** » May 12th, 2011, 8:58 pm

Wow that's a tough one

by **SIXSEATER** » May 12th, 2011, 9:16 pm

im starting to think could there possibily be a bad earth somewhere near the relays or even the starter. ahhh, will check tommorro now.

by **iCER** » May 12th, 2011, 11:05 pm

probably best to call an auto electrician.

by **ROOSTA** » May 13th, 2011, 9:42 am

Lets clear up a few things..

'Have recently noticed that my car wont start when trying to crank over...'
So is the problem the car wont start? Or that it wont crank?

'A few ppl have said to try disconnecting the Battery positive terminal while the car's cranking and if the car switches off on its own then its a faulty Alternator but mine seemed fine.'
I have never ever ever heard of this as a test.. Yes i have heard of doing that while the car is running but not while trying to crank it over.. I would suspect if you did it while trying to crank over that the car would stop ever time as the alternator cannot generate enough power to run the starter motor..

Cheers,
Nik

by **holmsy** » May 13th, 2011, 12:03 pm

yeh i think you need to look at your whole post and make it make sence.

cranking is not the same as running.

by **SIXSEATER** » May 13th, 2011, 1:34 pm

yeah sorry meant while its running......

anyways.....

Took the car to my local mechanic who checked if the battery was draining itself with the multimeter but all seemed fine so after all the testing he says my battery is nackered. So i took it back to the place i bought if from and they said theyll do some testings and get back to me in the morning.....

by **SIXSEATER** » May 14th, 2011, 3:12 pm

Ok guys, problem solved. Turns out I had a faulty "new" battery!
Received a phone call this morning after some testing's were done and yeah the battery was cactus, so the sales man offered me a refund or a brank new direct replacement battery which i happily took.
He also said i just happened to be unlucky as the return rate for a faulty new battery is 0.01% but if this new one fails again then I get another new battery or i would need to upgrade as it might not have been strong enought for my car..

cheers.