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Bad Alternator?

i currently own a 2002 Hyundai sonata that was purchased brand new

i have mostly kept up with the general maintenance spark plugs, air filters, oil changes, etc. but have been lenient on some of the less noticeable things such as belts

background history:

my car’s alternator has tested fine at multiple places (Walmart and advance auto parts) but when i had tested it, it had only produced around 30 amps when it was built to producing about 90, i assume this is because of a bad diode

i thought i could just use it until it completely died (despite the fact that it could harm my battery) because I’m still in school and cant afford a lot at the moment, but last night when i was driving home (it was wet out with deep puddles) and i drove through a rather deep puddle with a lot of water getting into the engine compartment.

(i have driven this car through many puddles some making a much larger splash, with no problems what so ever.)

shortly after i left for work and my batter light was on, i tried different things like turning the ac on high to see if they worked better at high revaluations to find out whether it was the battery or the alternator, as it turns out the fan maintained a constant speed and after work my car started, i got about 20 feet and it died,

my Friend came to charge my car but when he jumped me, the alternator started working again even though not 30 minutes ago it was not,

the same thing happened to me today (same puddle same rout) the alternator didn’t work going to work and it miraculously did when i went home

my alternator is obviously bad and needs to be changed, but is it the alternator causing this problem, or something else?

[i] i have mostly kept up with the general maintenance .. but have been lenient on some of the less noticeable things such as belts [/i]

my alternator is obviously bad

Maybe it is bad or maybe not. I would look at the belt first. It may need to be adjusted or replaced

[b] He who saves the most on maintenance spends the most in the long run. [/b]

I would also want to check the connections to the battery, starter and alternator. Remember each wire has at least two connections and you need to check both.

This sounds like a serpentine belt that’s slipping when it gets wet, in which case you’d need a new belt and possibly a new tensioner.

As for ignoring other belt maintenance, are you referring to the timing belt? If so, I’m fairly sure your car has an interference engine, so are you prepared to buy a new engine if you let it break?

Have the alternator AND the battery tested. You’re assuming the alternator is bad but you didn’t tell us anything about the condition of the battery. A good alternator will go bad trying to charge a worn out battery.

Your car is old enough to need a new timing belt. If it breaks the engine will suffer internal damage. This is crucial maintenance on this car.

While the timing belt is being replaced new accessory drive belts should also be installed, which should eliminate the possibility of a slipping alternator drive belt.

the battery, is in fair condition and has been tested repeatedly and is under 1 year old

as for the serpenting belt it has been replaced before but will need to be replaced again soon
(my car has a timing belt and 2 other belts) however they appear to be in good condition and a decent tension, but I’m not experienced in that area

a retired auto mechanic i talked to suggested that it could be a bad ground?

after driving through a puddle my alternator has stopped and has yet to work again despite the fact that it is completely dry

this question is a little off topic but, if my alternator happens to die repeatedly i would prefer not to have my hood open with a charger sitting there (at risk of theft) so i was wondering, in the trunk of my car i have an amp and capacitor,

now on on of the posts on the capacitor i have a 2 gauge wire leading to the battery then to the capacitor and then from there to the amp and the other post is a ground (about a 6 gauge wire)

would i be able to connect the battery charger to the posts?
considering that the one wire leads directly to the battery and the other to the Chase and then to the battery

Most likely you have a warning light lit that looks something like a battery on your dashboard. This means your car is either undercharging the battery or the battery cannot hold the charge.
The general remedy is both a new alternator and battery and a new serpentine belt. The cost is around $350.
The battery might be fine if it is new. If it is new, have it tested after the alternator and belt is replaced.
If it is old (five years +), replace it with the alternator.
A bad battery can ruin an alternator, especially if you had to jump start the car.

It sounds like maybe you aren’t clear about what they’re trying to tell you about the timing belt. Disclaimer: I didn’t know what it was until I started reading this site.

How does your timing belt look? (That’s a trick question.)

alright so, the alternator stoped working again…

so i used my vat-40 to test the alternator to make sure that that was the problem, and it turns out that it is,the alternator didn’t even flicker the amps needle

about a day or so later the alternator randomly started working again (it has been warm out and the alternator has been dry for quite some time yet it didn’t start working till about a day after)

because of this i assume the problem is before the battery and unrelated to the belts (because that wouldn’t stop working randomly)

the wires don’t appear to be loose and it’s not something a simple hit to the alternator would fix…

anyone have any ideas?

You bought it new but how far have you driven it? My idea is that you need a new alternator. If it has over 100,000 miles on it, take the alternator apart and check the brushes. If they are about a quarter of an inch long, they should be replaced. If they can’t be replaced easily, get a rebuilt alternator. Alternators quit on their own without anything else causing a probem most of the time. The voltage regulator is probably inside it. The alternator could run out of miracles soon.

Replace the alternator. I’m betting the brushes are shot, and this on/off action is damaging the commutator. Your spending more time and energy fighting the inevitable than just replacing the problem and being done with it.

Change the belts while you are at it, and if you need to, save up some money and get that timing belt replaced as soon as possible. Your on borrowed time and playing Russian Roulette with the timing belt that will cost you an engine if you keep putting it off. This belt was due to be changed at 60,000 miles or 7 years. Both the 4-cyl and 6-cyl engines are interference with timing belt-driven water pumps. A broken belt means ruined engine ($$$).

If your alternator was putting out 30 amps instead of 90 you just found your problem…YOu need an alternator…you will have a wide array of issue stemming from a bad alternator and it wil drive you nuts to figure out…I think you already got it…bad alt…

alright, thanks for your input,

i just needed to make sure their wasnt another problem that could damadge the new one

No the alternator is self encompassed with the voltage regulator inside it…so I am betting on the alternator