Car advice

[Seshat]

Some mechanics - especially auto-electricians - refurbish old alternators. If your mechanic can get you a refurbished alternator for your car, that can save you heaps.

The most common cause of an alternator failing is the contacts wearing out, and they're replaced with brand new ones in a refurbishment, so a refurbished alternator is almost as good as a brand new one.

[Exaspera]

Regardless if the car was checked or not, the alternator can still just die suddenly. I'm putting my $$$ on that, too.

[pitmonkey]

A bad alternator will kill a battery very Quickly. When the car is running is there a whining or grinding noise? If there is that usually the alternator making that noise, not good.

[fireheart]

A bad alternator will kill a battery very Quickly. When the car is running is there a whining or grinding noise? If there is that usually the alternator making that noise, not good.

Slight whistling noise.

At one point there was a puttering noise, which we worked out to be due to the immobiliser kicking back in at some point (possibly after a stall) and not being turned off. We're now looking at getting said immobiliser replaced....which begs to some questions:

1) Can someone please explain the various types in laymen's terms?

2) What would be recommended? The one I have at the moment consists of a remote control with one button that you use to click the immobiliser off. The car does not have keyless entry.

[fireheart]

OK, update.

We tested the battery by leaving the immobiliser OFF overnight. Testing it again...and there's no charge yet again.

So it's either two things: alternator or battery.

[wolfie]

He's doing a "process of elimination" sequence.

As we've had problems with the immobiliser before, he's testing that first.
The plan he's got in mind is somewhat similar to blas's, but with the basic plan as follows:

1) Charge it up (we have a battery charger)
2) leave it overnight without a part running.

I should add as well that the first two times the battery went flat were due to the lights not working. Could it be from the timing belt since it's apparaently meant to be looked at (various sources go between 90,000-100,000kms)?

One cheap test is to get the car started, turn on the dome light, and let it idle. If the light is flickering (and gets brighter and steady when you rev the engine), you're getting your electrical power from the alternator (i.e. dead battery). If it's bright and steady, the battery is good. Note that this is also a good diagnostic for a "no start" condition - if the dome light dims a lot when you crank the engine, there's not enough "juice" in the battery, if it doesn't, something is keeping the "juice" from getting to the starter.

Does it have the stock radio or an aftermarket one? If aftermarket, the installer may have wired the "run" power to an unswitched circuit (should be on an "accessory" circuit, with the "keep the memory alive" power to an unswitched circuit). A former co-worker had a Mazda 323 that kept running down its battery for this reason.

Is the trunk light switch working, or does the light stay on when the trunk is closed? You'll probably need to fold down the back seat to check this out. My previous car had this problem when the trunk latch wasn't adjusted properly.

Do you have a multimeter with ammeter function? Turn off everything in the car, disconnect one battery cable, and hook the ammeter into the circuit to see how much current is being drawn (stuff like the radio "keep the memory alive" will draw some current, but anything over 100 mA is most likely due to something staying on that shouldn't).

On most cars, the recommended timing belt change interval is around 4 years/100,000 km (60,000 miles), whichever comes first. If it's had the belt changed, the mechanic should have put a sticker somewhere near the "front" of the engine (with the belt-driven accessories - on my car, it's at the left end) with the date and mileage when it was changed. If there's no sticker, assume it's outdated. If you don't follow the change interval, the belt is good for about 1/10 of a second less than the life of the engine.

[Andara Bledin]

An easy way to check if it's the battery.

Charge it up and let it sit overnight with the cables unhooked. Then you know, beyond a shadow of a doubt, whether it is holding a proper charge on its own.

^-.-^

[fireheart]

An easy way to check if it's the battery.

Charge it up and let it sit overnight with the cables unhooked. Then you know, beyond a shadow of a doubt, whether it is holding a proper charge on its own.

^-.-^

That's exactly what my dad did.

Left everything unhooked overnight, thing was still losing charge.

So time to go battery shopping....

[Midorikawa]

Still advisable to check the alternator with the new battery, as a bad alternator will eat batteries like M&Ms. Make sure the alternator is putting out a steady 13V (I presume this is a newer car and the voltage regulator is internal.) Make sure it's putting out <whatever amperage your car needs> as well. This would be found in a shop manual. I don't know if you can buy shop manuals like you can here, but any auto parts store in the US has a section with car manuals that you can get for specific cars.

I have one for all 3 cars we own, and it walks you through a total rebuild, and has specs for every aspect of the car. I've found it to be infinitely helpful when tracking obnoxious issues in the wife's car, or the Jeep. The Duster I pretty well know every nook and cranny of and don't need the manual save for part numbers of seldom replaced parts.

[fireheart]

Bit of an update.

My mum talked to our neighbour, who is a mechanic for roadside assistance. His recommendations are as follows:

1) batteries only have a shelf life of about 3 years tops.
2) if the date on the battery is 2007, then electronics need to be checked.
3) have my mum take it to work with her one day a week to keep the battery awake.

[HYHYBT]

That depends on what you mean by "shelf life." You certainly wouldn't want to buy a new battery that's three years old, but they normally last longer than three years in the car, unless something else is wrong (such as repeatedly running it dead)

[Becks]

Speaking of batteries, it turns out that the Jerseymobile was still running on the factory installed battery.

Why is that somewhat impressive? It's a '99 Dodge Intrepid that the MOTH™ seems to want to run into the ground.

[Imprl59]

I think the OP has likely found their problem but here are a few tips for others that run in to this problem in the future.

You car has a charging indicator light that should come on when you turn the key to run but before you start the car. Usually a light that looks like a battery. Once you start the car the light goes out. This isn't a perfect thing... If the light goes out you could possibly still have charging problems but if the light stays on you KNOW you have charging problems (alternator). Also this light tells you nothing about whether the battery is good or not.

As with many things electronic if you have an alternator tested and it passes that means it was working "right now". This is no indiaction that it will be working five minutes from now. Without removing the alternator from the car and taking it apart no one can tell you anything about except it works or it don't.

People also get tripped up thinking that "my battery is new, it can't possibly be bad". While a new battery is less likely to croak than an old one you still want to have it tested before you rule it out. Batteries aren't made like they used to be.

If you ever have problems with the charging system take your car to one of the auto parsts chain stores. Most of them have a device they can connect to the car that will test the battery and charging system for you. They do it for free in hopes of selling you whatever part you need and it takes only a couple of minutes. Remeber though that if the charging system isn't working properly once the battery drains the car dies so turn off everything you can, don't go far and have a backup plan just in case.

It was mentioned here that you can disconnect the negative cable with the car running to check the alternator. That is the way we used to do it before cars were computerized but you don't want to do that on any car made in the last 25 years or so. A side benefit of a car battery is it can soak up and even out any power disturbances coming out of the alternator. A broken alternator can put out some really messed up power. The battery will help even that out but if you pull the negative battery cable the cars computers are then directly exposed to this potential dirty power from the alternator. By pulling that cable off you can blow out the computer(s) in the car and turn a relatively inexpensive repair in to a multi thousand dollar repair.

Hope I didn't bore you tooooo bad
Steve B.

[fireheart]

Alternator is working fine.
Battery was replaced and is running perfectly!
I've been able to run the car for a fair few trips now.

We've also worked out a system to ensure that the battery doesn't die, which is working perfectly around my work schedule. Basically, if I don't have a close shift or finish too late, dad'll let me drive home from work. Even though it's only a 10-minute trip (or 20 if I need to throw in petrol), the car still gets a good workout.

Also, twice a week I've been going out for driving lessons with my dad. These are unpaid ones, although I'll be doing paid ones soon (once my tax refund comes in) and going from there. Basically, state law requires that I log 50 hours of driving (10 of those have to be at night-doing OK so far) and pass either a driving test or get "modules" signed off as I have my driving lessons. (I'm most likely going for the latter). In short, every time I drive myself home from work, that counts as 10 minutes towards the 50-hour goal.

Adding up the total so far, these are the totals from day and night (these are in minutes):

Day driving: 813 minutes
Night driving: 181 minutes
Total: 994 minutes. (so almost 1/3 of the way there. 50 hours=3000 minutes)