Do alternators slowly die?

[cat007]

I stalled tonight on the motorway in traffic and when I went to start the car, the battery was dead flat.
The battery is pretty new - but when I was driving along at about 3,000rpm, with my headlights and spotlights on my volts, according to the stock voltage gauge, looks like it was less than 11....

When I drive around during the day without any accessories the voltage is over 13.

I haven't checked what the actual voltage out of the alternator with a volt meter yet.

Just wondering if an alternator can produce a lower amp output when the they start to die?

[sergei]

Most likely brushes are worn out.. Easy to fix if the slip rings are fine.

[cat007]

It also wines a lot. Thought it was the power steering pump as that's what it sounds like but it goes away when you take the P/S pump off.

I'll take it off tomorrow and see if I can inspect the brushes without any special tools!

I'm guessing brushes are probably pretty cheap

[Grrrrrrr!]

It also wines a lot. Thought it was the power steering pump as that's what it sounds like but it goes away when you take the P/S pump off.

err, typo or brainfart?

[cat007]

Haha brain fart. Too much beer haha

I meant when I take the p/s pump off the sound DOESN'T go away

[jacobrjett]

hmm. my battery always seems like its on the verge of dying. and I too get a whine. what does the whine sound like? i thought mine sounded somewhat like a supercharger whine, i assumed it was just because i dont have the cam belt covers on and they were making more noise then usual, and thought it sounded kinda cool will be funny if it actually turns out to be a crappy alternater.

[cat007]

Yeah a supercharger whine is a pretty accurate description!

[cat007]

Here's an example of what mine sounds like - old video but same alternator....

From about 40 seconds you can clearly hear it.

http://www.youtube.com/watch?v=-E6IvNrvqnw

[matt dunn]

Yes,

not that common on the toyota alternators but it does happen and sounds like your fault.

the diodes in the alternator crap out which causes lower amp output than normal.

When this happens you also get a whine from the alternator,
and excessive heat buildup too.
You may fell the alternator and it will be hotter than the engine is.

My bet will be the rectifier or the stator in the alternator are faulty.

Also when this happens the warning light function still works like normal.
99% of the the time the light will come on when it brushes,
and won't come on when it is rectifier or stator.

[BZG Wagon]

Yeah - one new years many, many years ago the alternator slowly started to die on the way back from Whangamata.

First the dash lights & headlights started to dim, then the car started missing and we had to drive in a lower gear, dash warning lights started coming on, by the time we reached the bombays we had virtually no lights and we drove in 3rd / 2nd to get to the top.

Eventually the car just stopped and nothing worked (20 meters from home fortunately).

Replaced alternator next day and all was fine.

[Stott69]

How do you test them? Im getting dimming lights n stuff and I know the batterys only a few months old

[jacobrjett]

dimming lights ae,

sometimes when I first start my car, I actually see the lights dim when i use the indicators

Maybe I have the same problem as you. I have been assuming for a while I just needed a new battery though, as mine was lying around for around 2 months without a charge

[cat007]

Picked up an alternator from pick a part for $45. Works mint now