battery troubles

[lx mike]

Well at work i moved my car around abck so i wouldn't have to walk so far to the parking garage and when i went to go home all i got was a "click" and then nothing. i check the terminals and they are tight. I got a boost from mt friend and when we took the cable off my battery the lights would dim and engine would surge and then die. we tried again and left them on a bit longer before jumping and got same thing. the second time we did it i watched the ammeter and it would go down to almost the bottom and jump back up when surging, It did take a while to start. when we first tried it turned over slowly and we let it sit a minute then tried and it started. second time we let it sit and it turned over just enough to start but not as quick as it usualy does. is it my battery or maybe the cables or soemthing else i can check??

[Maroon 5.0 LX]

Sounds like an internal short in the battery... go have a load check performed on it.

[PKRWUD]

I think it's the alternator. Once the engine is running, the battery really isn't used anymore. The alternator supplies the voltage that the vehicle needs to run. If it stumbled after disconnecting the jumper cables, then you were running of your friends alternator, and when you put the load on yours, it failed.

Try this. Get a flathead screwdriver, and with the engine running, carefully set it against the back of the alternator case (be careful not to touch any wires or connectors). If you alternator is working, you will be able to let go of the screwdriver, and it will not move. A properly functioning alternator creates a magnetic field, which will hold the screwdriver to the case. If it falls, there is not a sufficent charge being generated to create the magnetic field.

Take care,
~Chris

[Kamaro Killer]

it also works if you put the screwdriver on the pulley on the front.

[lx mike]

My brother gonna come on my lunch break and give me a hand. i have a multimeter to use.

Chris: if it's the alternator then why would it be ok when i would rev it to 1500? Could it be going and not charging at idle speed?? or do they just either work or don't??


i will try the screwdrive in back to see and hopefully can at least get it home, i think i'm gonna be talking to the security guards today about where i am parked!!

[PKRWUD]

Originally posted by Kamaro Killer
it also works if you put the screwdriver on the pulley on the front.

You funny man.

Careful Keith, someone might take you seriously about that.

[PKRWUD]

Originally posted by lx mike
Chris: if it's the alternator then why would it be ok when i would rev it to 1500? Could it be going and not charging at idle speed??

Sure. have you ever seen the headlights on a car with a weak alternator? The get dull and flicker at idle, but become brighter as the rpms increase.



Take care,
~Chris

P.S. A multimeter is a better way of testing the alternator output, but the screwdriver trick works great in a pinch.

[lx mike]

well got the car home. my brother borrowed a good battery and stopped by at lunch and we got my car running and out of some lady parking spot! she left me a note.
tried the screwdriver in back and there was a magnetic pull. I just got home and tried the multimeter and here what i got for readings. car off no light on at all it read 12.7 volts. start car and just at idle nothing else on it was still at 12.7 volts, rev engne to 1500 and would go to 14.3 volts. engine running, lights on , radio on, at idle 12.6 volts and when i would rev to 1500 would go to 14.3 volts. i'm gonna charge up the old battery tonight and see if it hold a charge or not. did notice fluid seeping out from under the negative post when we was changing them out. I've had the car for 2 years with this battery and i imagine it must be 3-4 years old

[PKRWUD]

The alternator is functioning, just not up to specs. I suspect that your new battery will become drained in the next day or two. Your meter should have read no less than 13.6 with the engine running.

Take care,
~Chris