How do you explain this car charging system problem?

[NeoPTLD]

I was hanging out with a friend last night and I got a call shortly after he left that his car's electrical system have failed. He described that lights got dim, radio dropped out and fan slowed down. These things happens when the charging system is not sustaining the load and load depends on battery until it is drained.

I got to his car(1988 or 89 Mazda 323 or something), got it jump started, but as soon as the jumper cable was disconnected, indicators dimmed then it stalled. We abandoned his car and I took him home.

He called me this afternoon and told me his car is fine now. He said he had this happen to him before and replacing the battery fixed the problem. Seeing how it self corrected, I don't think his battery replacement fixed the problem. The rest in between break down and installation of new battery must have allowed the charging system to correct itself.

Anyone have a clue what is likely to cause the charging system to fail part time?

 

[RagingBITCH]

Alternator?

 

[flot]

Uh, yeah, the battery was bad and he replaced it.

 

[NikPreviousAcct]

My girlfriend had this exact problem, but changing the battery didn't help. She had to replace the alternator. Her car died just like you'd said but we let it sit for a few days, then it just started right up. After that, it had the same problem again. Replacing the alternator has had her car running like a champ.

 

[Thegonagle]

This is a dead-simple one. His alternator is dead.

Expect to be giving him another ride tonight.

 

[Mark R]

Loose wire, failing alternator, failing alternator warning light (yup, this bulb is a critical part of the circuit).

I would suggest very carefully checking all connections to and from the battery and alternator - ideally, you should clean and remake each and every connection.

Ensure that the alternator is clean, that there is no physical damage, and that the drive belt is tight. Consider replacing the alternator.

A defective battery usually won't cause these problems, but this problem will very quickly destroy the battery.

 

[Wingznut]

Most likely it is the alternator... But it could very well be a bad connection (i.e. battery cables, ground cable, etc...)

 

[NeoPTLD]

Originally posted by: Mark R
Loose wire, failing alternator, failing alternator warning light (yup, this bulb is a critical part of the circuit).

I would suggest very carefully checking all connections to and from the battery and alternator - ideally, you should clean and remake each and every connection.

Ensure that the alternator is clean, that there is no physical damage, and that the drive belt is tight. Consider replacing the alternator.

A defective battery usually won't cause these problems, but this problem will very quickly destroy the battery.

If what you say is true, that's a horrible engineering.

 

[mattgyver]

Go to AutoZone or other parts store. Most places will test the battery and altenator for free. Then you'll know what needs replacing.

 

[Zenmervolt]

Originally posted by: NeoPTLD

Originally posted by: Mark R
Loose wire, failing alternator, failing alternator warning light (yup, this bulb is a critical part of the circuit).

I would suggest very carefully checking all connections to and from the battery and alternator - ideally, you should clean and remake each and every connection.

Ensure that the alternator is clean, that there is no physical damage, and that the drive belt is tight. Consider replacing the alternator.

A defective battery usually won't cause these problems, but this problem will very quickly destroy the battery.

If what you say is true, that's a horrible engineering.

No it's not. If the alternator dies, everything runs off the battery and the battery is not being charged. A fully charged and new battery will be able to run everything for a little while, but as the battery runs down, lights dim, the radio drops out, the fan slows down, and eventually the car stalls because the coil isn't getting enough juice.

ZV

 

[NeoPTLD]

Originally posted by: Zenmervolt

Originally posted by: NeoPTLD

Originally posted by: Mark R
Loose wire, failing alternator, failing alternator warning light (yup, this bulb is a critical part of the circuit).

I would suggest very carefully checking all connections to and from the battery and alternator - ideally, you should clean and remake each and every connection.

Ensure that the alternator is clean, that there is no physical damage, and that the drive belt is tight. Consider replacing the alternator.

A defective battery usually won't cause these problems, but this problem will very quickly destroy the battery.

If what you say is true, that's a horrible engineering.

No it's not. If the alternator dies, everything runs off the battery and the battery is not being charged. A fully charged and new battery will be able to run everything for a little while, but as the battery runs down, lights dim, the radio drops out, the fan slows down, and eventually the car stalls because the coil isn't getting enough juice.

ZV

I was referring to what I highlighted. I was saying a charging system that is dependent on indicator lamp as a resistor for normal operation is poorly engineered.

 

[olds]

Originally posted by: Wingznut
Most likely it is the alternator... But it could very well be a bad connection (i.e. battery cables, ground cable, etc...)

 

[Zenmervolt]

Originally posted by: NeoPTLD

Originally posted by: Zenmervolt

Originally posted by: NeoPTLD

Originally posted by: Mark R
Loose wire, failing alternator, failing alternator warning light (yup, this bulb is a critical part of the circuit).

I would suggest very carefully checking all connections to and from the battery and alternator - ideally, you should clean and remake each and every connection.

Ensure that the alternator is clean, that there is no physical damage, and that the drive belt is tight. Consider replacing the alternator.

A defective battery usually won't cause these problems, but this problem will very quickly destroy the battery.

If what you say is true, that's a horrible engineering.

No it's not. If the alternator dies, everything runs off the battery and the battery is not being charged. A fully charged and new battery will be able to run everything for a little while, but as the battery runs down, lights dim, the radio drops out, the fan slows down, and eventually the car stalls because the coil isn't getting enough juice.

ZV

I was referring to what I highlighted. I was saying a charging system that is dependent on indicator lamp as a resistor for normal operation is poorly engineered.

Ah. My bad. I didn't even notice the bold.

ZV

 

[Liviathan]

Get the car started....unplug the battery. If the car dies you Alternator is bad...if not..then is magic!

 

[NeoPTLD]

Originally posted by: Liviathan
Get the car started....unplug the battery. If the car dies you Alternator is bad...if not..then is magic!

This is not good for electronics. The battery smoothens the output of the alternator as well as provide a reserve. You can damage your computer and other electrical system onboard when you do this.

 

[Zenmervolt]

Originally posted by: NeoPTLD

Originally posted by: Liviathan
Get the car started....unplug the battery. If the car dies you Alternator is bad...if not..then is magic!

This is not good for electronics. The battery smoothens the output of the alternator as well as provide a reserve. You can damage your computer and other electrical system onboard when you do this.

Quite so. Though this is a viable practice for older cars with carbs and no real computer systems.

ZV

 

[Mark R]

Originally posted by: Zenmervolt

Originally posted by: NeoPTLD

Originally posted by: Mark R
Loose wire, failing alternator, failing alternator warning light (yup, this bulb is a critical part of the circuit).

I would suggest very carefully checking all connections to and from the battery and alternator - ideally, you should clean and remake each and every connection.

Ensure that the alternator is clean, that there is no physical damage, and that the drive belt is tight. Consider replacing the alternator.

A defective battery usually won't cause these problems, but this problem will very quickly destroy the battery.

If what you say is true, that's a horrible engineering.

No it's not. If the alternator dies, everything runs off the battery and the battery is not being charged. A fully charged and new battery will be able to run everything for a little while, but as the battery runs down, lights dim, the radio drops out, the fan slows down, and eventually the car stalls because the coil isn't getting enough juice.

ZV

That is certainly true - the battery will discharge without the backup of the alternator. By the time the car stops, the battery is deeply discharged. Car batteries (with the exception of super-premium types e.g. optima) are designed not for discharge, but for starting only. Discharging a battery completely, even once or twice, can significantly damage it - especially if the battery is left discharged for a few days.

If you have had a charging system failure on your car, then it is a false economy not to replace the battery - as it will likely have sustained significant damage.

As to the warning light - it comes down to the fact that alternators are not 'self-exciting'. They have to power-up the internal electromagnet before they can start generating electricity. This power runs from the battery via the 'alternator warning' light. If the bulb fails or is loose in its socket, then no power can flow to start the alternator.

 

[NeoPTLD]

Originally posted by: Mark RAs to the warning light - it comes down to the fact that alternators are not 'self-exciting'. They have to power-up the internal electromagnet before they can start generating electricity. This power runs from the battery via the 'alternator warning' light. If the bulb fails or is loose in its socket, then no power can flow to start the alternator.

Even cheapo Chrsitmas lights have a better redundant protection. When the filament fails, it causes the full line voltage across the lamp which breaks down the insulation on insulated waire wrapped along the base of the filament leads.

 

[db]

Could be a slipping alternator belt, or
your friend is filling the battery too much with water, so it overflows out the holes when it tries to charge and shorts out between the two terminals.

 

[AntMan530]

check the battery connectors for corrosions. if theres like white puss or hairy stuff..clean up