car troubles HELP!

my moms car died on her while she was driving. It had previousely had the "low battery" light on. Cornkid jump started it, and she was able to make it home. But now it doesnt start again.... what gives?? The battery is brand new (1-2yrs old).

-David

Sounds like the battery isn't charging. Could be a bad alternator (generator) or a bad voltage regulator. Maybe the belt to the alternator has come loose/off so the engine isn't turning it anymore (if it has a separate belt). Latter would be cheapest fix. New alternator would be most costly (minimum would be maybe $150 parts plus labor, on up, depending on the type of car and type of mechanic you have).

If it's the "ALT" light then the charging system voltage is lower than the battery voltage... depending on the year/make/model of the car it is usually the voltage regulator or alternator. But I would not rule out a loose/rusty connection on the battery or alternator.

If you have a volt meter you can check it... with a hot engine the charging system voltage should be in the neighborhood of 13.5 to 14.2 volts. If the charging system voltage is in this range it's probably the battery.

oh geez, it is probably the alternater ... and it would cost well over $1000 to fix.... our mechanics are crooks.... in fact, one of my brothers cracked a light on our jeep and it was a $600 fix! Mostly because the stick went through the light and a plastic frame in the back that held it in.... so he had to get the light, a new plastic frame, and then labor.... still not worth 600 bones in my opinion.

-David

Could be a simple as a lose connection somewhere - that's what was "wrong" with my car's battery...

just checked the voltage of the battery while the car was off and we got 12v. Then we turned it on and let it run, and it went down to ~10.8....

as the car runs, the battery loses power... as it sits, it recharges... What the HECK!?!?!?!?

-David

Sounds like a bad alternator to me. You should do a few tests before changing it though. Reseat the cable that plugs into the alt and clean your battery posts.

Batteries slowly regain a little voltage as they sit. Not much capacity, though. The voltage also dips down as power is withdrawn. If the engine's running and you're only measuring 10V at the battery (should be 13+ when charging) sounds like the charger circut's bad. Check the wiring, check fuses, then try measuring right at the alternator.

What kind of car is this? If anyone charges you $1000 to replace an alternator and it's not a Lamborghini or the engine doesn't have to come out, they should be stuffed into the trunk.

Take the car to Autozone, if you have one. They'll hook up to a machine in the parking lot for free and tell you whats up. Call 'em first to confirm what I say.

Buy the alternator there, if thats what it needs, and take it to any Billy Bob gas station mechanic who can install it. Whole thing might cost $300 - $400, not a grand.

I think you can by rebuilt alternators too.

Might get lucky and just need a new battery or voltage regulator.

Contact CPF member Fivemega, who can make for you a battery carrier that lets you use 80 AA NiMH to replace your car battery.

Just kidding.

cheers

Start simple. Check the electrolyte (if it's not sealed), clean and tighten the terminals and clamps then follow Mr. Noodles advice and have an auto parts store check it - should be free. Depending on the car, you shouldn't be out more than a couple of hundred, worst case.

Do NOT take it to dealer or BrakeChek, etc. Most indys will give you a turnkey price over the phone.

it is a 1998 Chevrolet Astro. We will take it to Auto-zone and we'll see whatz up.

-david

Sounds like the alternator to me too. If the belt is slipping, you would know as it'll make this horribly loud squeel.

An alternator should be very easy to replace, do not let anybody charge you more than $500 (at the very very worse). People have given good advice here already.

As for the light, $600 might not be too far fetch depending on the car. Lights are expensive, not $600 expensive, but more than what you think.
Should have also replaced it yourself, go to the junkyard and find a good one, and the actual labour part shouldn't take more than 10 minutes.

turns out our Autozone has no diagnostic equipment... now i'm back at square 1.

-David

call around. O'Reillys, Pepboys, NAPA......

called everyone, nobody has anything.... geez. Guess we'll have to take it to a mechanic. But he just said it would cost ~285.... uh hu..... i doubt it, but we'll see.

we are suspicious that it is not the alternator, but maybe the voltage regulator...

-David

I'm not sure, but I think that alt may have an internal regulator. O'reillys website shows rebuilt alt for 99.99$, so $285 is not far out of the ball park, particularly if it's a new alt.

On many cars (unfortunately not all) the alternator and the stuff that goes with it (voltage regulator, drive belt) can be replaced by any monkey that can hold a wrench...

For many cars, there are the Haynes workshop manuals, giving a detailed description on how to do the work...

Get junkyard or rebuild parts to save money...

But first of all, get a multimeter and measure everything... bad connections are often the problem. look for any sign of corrosion, look for loose connectors. measure every single fuse you can find in a 10 yard radius of the car (had a powerproblem in my car once, replaced every fuse twice, de-installed my complete audio install, replaced almost all wiring, still not working. Replaced a fuse in the powerbox of the houseboat where I lived at the time and the powerproblem in the car was fixed... go figure)

I had similar problems a few years ago. I replaced the battery and it didn't help. Thought it was the alternator.

It wouldn't start one day and I had my wife try to crank it while I was tugging on the wires, trying to find if I had a bad connection. Suddenly it cranked. After a bit more snooping, it turned out that the + battery wire had an OPEN! It had broken over time internally and when I held it just right, it worked. Problem solved for $30.

I don't know how mechanical you are, or how much time you have, but if you have an inkling of mechanical ability and a bit of time, try to wring out the connections first.

An alternator (and yours most likely does contain the voltage regulator) is something just about anyone can install. If you can run a wrench, spend $25 for a Chilton's Repair book (or Hayne's or similar) with step-by-step instructions and lots of pictures, and you can install a rebuilt alternator in a couple of hours (30 minutes the second time you do it!). Bigiron's numbers are what I would expect: about $100 for a rebuilt.

Biggy put you on the right track. 99% of the time is a loose wire or loose connection, or crap on the connection. remove, clean ( with a brush till the connects are shiny like a new penny), re-attach, regrease with battery grease or vaselline. check electrolyte levels.
start car, if you can, if the voltage isn't right, start jigglin' -- if no response then start thinking about replacement parts..

an even simpler possiblity; the battery is run down (leave the lights on overnight? radio? 12 volt curling iron?) and you haven't driven it enough to recharge it..?

It hasn't been mentioned, and I think it bears mentioning, that if you decide to swap the alternator yourself, disconnect the NEGATIVE battery post first.

The vehicle's chassis is negative ground, so if you disconnect the positive battery post first and the wrench touches sheetmetal... well, you can guess the rest, considering even a dead battery can push well over 200 amps through a wrench.

Also, the alternator has a large (usually red) wire going to it that is routed straight to the battery, so if you replace the alternator yourself do not attempt to work on it without first disconnecting the battery.

I don't mean to sound stearn here, but take it from a guy that replaced a dead battery on his 1968 Cougar and turned a Craftsman combination wrench cherry red in about 2 seconds by bridging poles!! (I was just glad there was no acid explosion!)

BTW, on the GM alternator there are two connections, the hot wire (+, to battery) and a plastic electrical plug. The plug controls the charging circuit and if it comes disconnected, reduces alternator output to zero. Negative contact is through the alternator body-bolted-to-engine-block, so also be sure the engine block is securely grounded. The alternator is most easily changed from beneath the vehicle... it's a dirty job but totally easy to DIY.

One more BTW, the charging circuit control is run by the ECM... if the wiring between the alternator and ECM is interrupted, you have no charging, but that's very rare.