Hello Everybody!
I hit 160,000 miles on my truck and just went through second alternator change. First time I did that when I had around 72,000 miles on the vehicle. That gives me an estimate that alternator is good for 80,000 miles.
Even though I have a new (re-build) alternator now I still cannot understand why only 80,000 miles? And if that's correct estimate or it is maybe just a bad luck?
I was towed twice and that's not fun... Kind of trying to look forward and get prepared for the next time....
Please all input will be appreciated... what do you guys think about the subject?
BTW, nothing serious so far (exsept alternators), knocks on wood...
Alex,

 

I've got 110K miles on my original alternator.

I've had two cars in the past (a Nissan Altima and a Honda Civic) that both had nearly 200K miles on them, in addition ot several other vehicles, and I've never had to replace an alternator.

But I have no idea what the life of one is supposed to be.

How are your alts failing? I wonder if your belt tension is too tight, causing the bearing to fail? Or is it more of an internal problem?

 

It fails like:
- forst of the battery gauge goes to zero
- then all other gauges (tax, speedo ets) go to zero
- all ligths go off
- ABS brake and the airbag lights go off
- the car stalls

I change the belt along with the alternator and I think that pretensioner is self-adjustable... so I would not think so...

 

Have you ever had a look at the brushes on the internal regulator? They can wear out too, causing the whole unit to fail.

 

both times mine's gone out the brushes were bad.the first time one of em was comepletly gone.the second time they weren't that bad and it seemed to be the regulator.so i went and got a new set of brushes and a regulator from oreiley's for about 50 bucks all together and it's been fine since.its a very easy fix if you have any mechanical ability and some basic tools.you will need some torx head bits,i don't remember what size,to get the regulator off,though.

 

Thanks much!
Thanks for trying to help me out on fixing the alternator...
But I was wondering if 80,000 miles on it is a reasonable estimate? Any thoughts on that please?
Alex.

 

I've had 2 go bad and I have 115K miles on mine. The factory one went bad because of excess mud riding. I bought an Advance Auto Parts one and had it for about a year, and it went bad. Thank god for lifetime warranty.

 

sorry,i meant to say somethin bout that too.mine seem to last about 60,000 or so.i changed the first one around 60,000 and i just had it go out not too long ago.i think the crappy battery i had before it went out this time was the problem.right before it went out i went and got a 1200 cca battery from co-op because we were going to memphis for my cousin's wedding and i didn't wanna get stranded with a dead battery.the battery light had been coming on like it did the first time it went out,but i thought it was mostly the battery.on the way back from memphis it started coming on for a while then it'd go off and on and off.then after about a week the alt went out.i still think it was mostly the battery just makin the alt work harder because it wouldn't hold the charge.i love the battery i have now,70 bucks without a core charge.cant beat that.i had one in my old truck and left it sittin for about 8 months and it still had 13.7 volts.i don't know where all they have co-op's,but its a great battery and helps out the alt alot not havin to recharge it all the time.

 

Thanks, guys!
way fast witey, isn't it like even though the battery might be good and alt doesn't need to charge it but still the brushes will be wearing off because the alt is spinning anyways?
I mean, it's good to have a great battery but alt will be working anyways, right? Or I am missing something?
It looks like 80,000 miles is good...
Thanks, Alex

 

I got 180k out of the factory installed unit on my truck, it made it through the first battery @150k. I did have to install a new battery at 189k, and this one (battery) acts like its not going to make it through the winter (thank god for warranties).

Who knows? Maybe just the luck of the draw.

BTW, 192k as of this morning.

Jamie D.

 

well,the more the alternator is actually used the more wear it puts on the brushes.that's what i thought but it doesn't really seem that way or nobody's alternator would last more than 60,000.mine always did fine till i put a crappy battery in there.then it started goin down hill.my original battery was fine when i replaced it.my dad was tradin in his expedition and we robbed the tires,wheels and battery out of it because he had just bought the battery and it still had a warranty.by the way,don't buy a die hard.i had 2 of em and they suck.

 

way fast witey,
Sorry, maybe I should not continue asking (dump) questions but I couldn't...
My car is like seven years old (made in 1997). I bought it in 2000. So it’s seven years old. I still use the battery I bought it with… So based on your perception and having that I change alts every 80,000 miles I would say that the battery was bad since the truck was made…

Maybe it’s a good idea to buy a new battery anyways…

Thanks a lot for your input, Alex!

 

My 95 Ranger had 155K miles when I traded it in back in July. I bought it new in the summer of 95. Still had the original alternator. Original battery went out about 9 months ago.

 

I have 87000 miles on my 98 Expy, alt is still going strong (knock on wood) and I have in addition to all the Eddie Bauer goodies running off it, I have a 1000 watt, 15 speaker sound system in it. But as luck will have it, I think my battery is getting weak, it is getting cold here in PA, and my starter is starting to crank very slow......