car won't charge..help.

[mkcman17]

my car isn't getting a charge. i have a greg g voltmeter installed, and driving home from school i noticed that the bars were diminishing - eventually to zero. the battery is strong and new, and holds a charge when when i give it an extended jump, but once the car is on it simply won't keep any power. i'm thinking it's a bad ground but i'm not sure...and i need my car to get back to school tomorrow so it's kind of important. i'm guessing the ground is the large wire?

[tonywonder]

Usually when ur battery is new and it dies while the engine runs its a bad alternator. So check your alternator.

[mkcman17]

it's been intermittent though. that's why i'm guessing it's wiring. it's only just recently begun to consistently not charge

[tonywonder]

I see what you mean. Alternators don't always just stop working flat out. They will gradually just stop functioning properly and then stop working. After you check the other things you think it is. Take out ur alternator and have it tested somewhere like pepboys. I think its free for the test. I had a semi functioning alternator in my honda for over a year before it finally gave out. And if u say its not keeping power the alternator is likely not providing enough charge to keep the battery alive. U can do a simple voltmeter check yourself or even ask a local mechanic to check it for you. All u gotta do is turn the car on and check to see how much charge the alternator is providing to the battery and compare that to what its suppose to be providing. Its a fairly easy procedure if u have a handheld voltmeter. And it wouldn't hurt to check just incase.

Trust me you don't want your alternator to fail and then ur battery to die while you are driving especially on a freeway. It has happened to me and shit was scary as hell. I managed to get the car home without a tow miraculously, and without stopping the car. It was tricky though cuz it kept wanting to die. And it was at night which is especially dangerous.

[mkcman17]

okay will do, i've got a local buddy coming to help me out. it just sucks that i punctured teh radiator on my truck the same night, so i literally have no wheels. i had to drive 17 miles home on 'zero' reading on my in-car voltmeter...i shut off everything for the drive, and when i got home putting up the windows with the car running nearly stalled it out. that's interesting you say that about alternators...i figured when they went out, they just went out. i'll get the bitch out tomorrow and go have it tested..

[StereoInstaller1]

To add a bit to what Tony said: an alternator has 3 "legs" ( I will leave the tech shit out) and if 1 fails, it isn't 33% of your voltage gone, it is 33% of your current. It also add to the stress of the other remaining legs, so they crap out quicker. When the 2nd one shits the bed you had better have towing available...

[mkcman17]

are there any tests to tell the difference between a bad alternator and bad wiring?

[StereoInstaller1]

Yes, of course. Test the alternator and inspect the wiring, that should explain just about anything.

[mkcman17]

well i can only see a couple inches of the wiring...the rest is all sheathed. i guess i'll have to take it out and test it in the morning...

[mikeedler]

is your alt. light coming on when you turn your ignition on to pos.2? If that bulb is burned out your car will not charge.

I also had an e30 years ago that the circuitboard on the rear of the guages had a bad contact and would sometimes not let the car charge.

[mkcman17]

is your alt. light coming on when you turn your ignition on to pos.2? If that bulb is burned out your car will not charge.

I also had an e30 years ago that the circuitboard on the rear of the guages had a bad contact and would sometimes not let the car charge.

Are you joking me?? That was exactly it...i had my spare cluster in and swapping back the main one fixed it no problem...i feel like a retard now haha..thanks guys

[StereoInstaller1]

They supposedly fixed that in January of '87, must be an early cluster.

Good job!

[e30fish]

I would have just drive to Autozone and have it tested on the car while running, its free. funny about driving around for a year on a failing alt. I'm currently waiting for mine to finally bite the shit. got an extra one waiting to be put in. my battery light stays on right now. hopefully, swapping in the functioning one will cure the light too

[jlevie]

They supposedly fixed that in January of '87, must be an early cluster.

I've seen original clusters from as late as 89 production that did not have the bulb bypass resistor. So make sure that the alternator bulb is good.