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Why do alternators go bad?

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12K views 14 replies 7 participants last post by  ShotgunTC88  
#1 ·
It seems to be a common problem on cars that get a bit long in the tooth...just wondering cuz a co-worker's honda needs a new alternator.

anyone know what the issues are?

Hg.
 
#2 ·
Yeah, I've had an alternator go bad on every car I've owned. always happens around 75,000 85,000 miles but it probably has more to do w/ age. A component in the alternator just dies, the diode. But there's more than one so it goes gradually.
 
#3 ·
the alternator produces a magnetic field and the energy is converted from ac to dc... the current is picked up by two carbon brushes in contact with slip rings. typically over time the carbon wears out and loses contact with the slip ring. maybe the stator windings just get dirty and corroded and worn. (these are usually the reddish wires you can see inside)

other than that, common alternator related problems are from the internal components failing, loose connections, the belt becomes loose or the battery is bad.
 
#4 ·
They are seduced by the power of the Dark Side.



...yeah, and as he said, the brushes that are forced to endure lots of friction eventually wear out. And, of course, just about anything can go wrong... things break. But that's a wearing down failure that eventually must happen.
 
#8 ·
Trainrex said:
Honda alternators typically have bearing problems. They usually end up seizing, and snapping the belt in a blaze of rubber smoke. I've changed more Honda altarnators than I can count.
really? how many miles were on these??? i usually change the belt when it makes noises, so i've never seen a "blaze of rubber smoke".
 
#10 ·
It seems that GM, at least in the '90's, ran a bit too much tension on their belts causing the bearings to go prematurally. I know I replaced the one on my '94 *cough* firebird *cough* at least 5 times in 115k miles. My wife has a '97 Saturn which has had it replaced a few times as well. Actually I just replaced hers again a few weeks ago. :sadwave:
 
#11 ·
zoinks said:
It seems that GM, at least in the '90's, ran a bit too much tension on their belts causing the bearings to go prematurally. I know I replaced the one on my '94 *cough* firebird *cough* at least 5 times in 115k miles. My wife has a '97 Saturn which has had it replaced a few times as well. Actually I just replaced hers again a few weeks ago. :sadwave:
From 1987 to 1994 GM's bearing/tensioner design left a little to be desired. From about 1989 to 1993 (approx) Ford had a problem with their internal voltage regulators, and connectors that regularly melted, and sometimes caught fire.
 
#14 ·
The only alternator I had die on me was in an 87 Sentra. The thing came with 2 speakers and a cassette player. Well, I was stuck with the damn thing, but I had some money to add a CD changer and upgrade the speakers. Since the power from the head unit was almost nil, I had to have amps for the speakers. Fortunately, my brother had spare sitting around. Anyways, I had all this professionally installed (I was in high school, unaware that my future would turn me into a car guy)... they never bothered to mention what would happen. About 4 months later I was driving home and I noticed my lights were dim... then the head unit turned off.... I managed to get home but it wouldn't start again. The mechanic was very nice while explaining to me that I was a dumbass.

Long, pointless story. I'm still at work, wanna go home.
 
#15 ·
Trainrex said:
I made it to 13 last time I tried :D

I can do 8x7=56!

Only because that ***** of a grammer teacher made me wear that goofy flashcard for a day cause I missed that one :unhappy:

Please, Let's not do speelllings

I lost an alternater in my Berretta because of the stereo set up.

Shotgun