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Old March 13th, 2018, 06:03   #1
charlieruu
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Default What's going on with my alternator?

So yesterday I was driving and my battery light would turn on for a few seconds and then turn off and it did this a few times. Later last night it stayed on and now this morning it is still on. I have a frost heater so the car started up fine this morning but my fans aren't blowing very hard and my windows roll up slowly. Also when I shut down the car it kind of makes a flutter noise. I checked the fuse box and the fuse is fine. So my question is, is it my pulley or is it the alternator itself? I am really tight on money so I'm not sure what to do because I can't afford an alternator right now. Thanks.
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Old March 13th, 2018, 06:06   #2
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It sounds like your alternator is no longer charging.

Easiest way to check would be to measure voltage across the battery terminals if you have access to a voltmeter.

Car off voltage should be aroung 12.0 - 12.5v Running should be around 13.5 - 14.5v

I would guess that you are lower than that. You are likely running on what is left in the battery - every electrical accessory you use empties the battery faster (like the windows and fan you mentioned).

If that is the case - then you are very close to having the car fail to start, or worse - stall out while you are driving. It is not safe to drive by your description.
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Old March 13th, 2018, 07:12   #3
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Originally Posted by Windex View Post
It sounds like your alternator is no longer charging.

Easiest way to check would be to measure voltage across the battery terminals if you have access to a voltmeter.

Car off voltage should be aroung 12.0 - 12.5v Running should be around 13.5 - 14.5v

I would guess that you are lower than that. You are likely running on what is left in the battery - every electrical accessory you use empties the battery faster (like the windows and fan you mentioned).

If that is the case - then you are very close to having the car fail to start, or worse - stall out while you are driving. It is not safe to drive by your description.
Yeah I'm wondering if there is a way to know if it is my pulley or if it's my alternator
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Old March 13th, 2018, 07:32   #4
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You can fully charge the battery (out of the car), then bring it to a parts store that tests batteries and alternators. That should tell you which is likely the culprit.

As far as checking the pulley, you could make aligning index marks on the alternator shaft and pulley and see if they move after the engine has run. Other possibility is a slipping belt. That, you would just check by feeling the tension on it. If the belt is slipping, you should also be noticing symptoms from other devices powered by that same belt.
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Old March 13th, 2018, 07:49   #5
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Quote:
Originally Posted by roni024 View Post
You can fully charge the battery (out of the car), then bring it to a parts store that tests batteries and alternators. That should tell you which is likely the culprit.
As far as checking the pulley, you could make aligning index marks on the alternator shaft and pulley and see if they move after the engine has run. Other possibility is a slipping belt. That, you would just check by feeling the tension on it. If the belt is slipping, you should also be noticing symptoms from other devices powered by that same belt.
Since you said that, my dogbone mount is shot and I'm just waiting on the bolts to arrive so I can install new bushings. My buddy had his belt snap from a bad dogbone mount. I believe he said it basically was pulling on it and causing it unnecessary tension. Could that be causing issues with the belt?
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Old March 13th, 2018, 07:53   #6
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Cheap trick on failing pulley: CAREFULLY push on the fan blades inside the alternator with a pocket screw driver - should feel some resistance but moves one way, should NOT move the other way. If you have to push hard enough to bend fins then its not going to move (most likely).

Usually fail locked up and causes some weird squeaking or rattling. Sometimes fails unlocked and will cause no charging.

Another test, if you have a volt meter /DVOM, is to measure voltage at big cable on alternator and compare to voltage at battery. Usually not this bad, but I have seen cable from alternator to battery(fuse box) loose voltage and under/not charge the battery.

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Old March 13th, 2018, 08:19   #7
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Based your miles and the intermittent nature of the problem at first I suspect it's the brushes.

Mine acted like this when the brushes and commutator(?) were worn. (Can't remember the term for what the brushes ride on in an alternator.)

I was able to get a few hundred miles out of mine while I ordered parts by removing the brush assembly and pulling on the brushes with needle nose pliers to stretch and straighten the wire behind them so they didn't fight the springs.

You can replace just the brushes if you can solder but likely the rub rings(?) are pretty worn too.

Replacing that assembly is more involved.

There's a write up with pichers and a source for the parts floating around.
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Old March 13th, 2018, 10:13   #8
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Quote:
Originally Posted by roni024 View Post
You can fully charge the battery (out of the car), then bring it to a parts store that tests batteries and alternators. That should tell you which is likely the culprit.
To clarify, I meant bring the entire vehicle with battery re-installed to the auto parts store for testing. My original post was poorly worded.

I don't think a bad motor mount or dogbone would cause your issue. The alternator is bolted to the engine and is powered by the engine. Any skewing of the assembly would be inconsequential to the alternator's output.

I'm leaning toward bad alternator at this point. As others have said, they can be rebuilt, but nowadays it makes more sense to just buy a new one. Or, if you can find a good used parts supplier with a warranty, you can go that route if you don't plan on owning the car for too much longer.

But, before you attempt replacing it, try to clean the wiring connections on the alternator and battery terminals. Dirty connections can cause the symptoms you describe.
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Old March 13th, 2018, 10:20   #9
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Before anything, measure voltage at the battery with the engine running.

Then check the one-way clutch on the alternator as above.
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Old March 13th, 2018, 12:13   #10
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I've got 371k Miles now on my 2000 and still have the original alternator and starter. My Starter has made the familiar over run noise for 8 years now. Just a little dust build up then it clears. You know how many people tell me my starter is going out.
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Old March 13th, 2018, 12:28   #11
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Who's talking about starters?
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Last edited by KLXD; March 13th, 2018 at 12:30.
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Old March 13th, 2018, 13:15   #12
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My alternator made it to 392,xxx miles before it died on way to work during a snow storm.
It was original. When I took the brush assy apart found the brushes were worn very unevenly, to the point the shortest one was flycutting the brush ring down 1/8 of an inch. I was amazed it produced power for so long.
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Old March 13th, 2018, 14:09   #13
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get a volt meter, test it and the battery.
do a search and see what others have to say.
this is the 12th thread i have seen this year on "battery/alt" issues that can simply be diagnosed with a multimeter.
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Old March 13th, 2018, 14:59   #14
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-Alternator gave a warning yesterday and then last night (all the lights ON, no doubt).
-Good battery rebounds overnight and starts car just fine with the advantage of a frost heater.
-Alternator still issuing warning.
-Battery taking hit because the DRLs are on.
-If there is no wild screeching, smoking rubber and noticeable vibrations, the ALT is spinning.
-The bad dog-bone has zero relation to the apparent issue.

As suggested, most likely the brushes have worn out. Yeah, some last a very long time! But, we have no history of this ALT or Car. Maybe the IP is leaking diesel fuel down on the ALT. Did the little cover and seal on the Voltage Regulator pull loose due to heat and allow water into the delicate electronics?

Yeah, check the voltage! What will that tell you? Battery is low, due to why? You can put an old weak battery in there and boost-start the engine. If the ALT is working properly, the RED light will not be ON as it charges up that old weak battery.

It's possible to remove the Voltage Regular (which contains the brushes) with the ALT on the vehicle. But, it is a challenge! 13mm, 15mm, 8mm, Phillips screw driver (or 8mm nut, depending), light to see, a mirror, etc. The 8mm wrench/socket is to remove the ground/strap for sure. When removed, if the brushes are the culprit, it should be apparent as others have suggested.

Removing the ALT is a challenge as well. Right Fan needs to be removed. The AC Compressor needs to be unbolted and dropped down out of the way. The Serp Belt needs to be removed and the Serp tensioner needs to be removed.

Keep us posted!
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Last edited by AndyBees; March 13th, 2018 at 15:02.
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Old March 14th, 2018, 05:39   #15
charlieruu
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Quote:
Originally Posted by AndyBees View Post
-Alternator gave a warning yesterday and then last night (all the lights ON, no doubt).
-Good battery rebounds overnight and starts car just fine with the advantage of a frost heater.
-Alternator still issuing warning.
-Battery taking hit because the DRLs are on.
-If there is no wild screeching, smoking rubber and noticeable vibrations, the ALT is spinning.
-The bad dog-bone has zero relation to the apparent issue.

As suggested, most likely the brushes have worn out. Yeah, some last a very long time! But, we have no history of this ALT or Car. Maybe the IP is leaking diesel fuel down on the ALT. Did the little cover and seal on the Voltage Regulator pull loose due to heat and allow water into the delicate electronics?

Yeah, check the voltage! What will that tell you? Battery is low, due to why? You can put an old weak battery in there and boost-start the engine. If the ALT is working properly, the RED light will not be ON as it charges up that old weak battery.

It's possible to remove the Voltage Regular (which contains the brushes) with the ALT on the vehicle. But, it is a challenge! 13mm, 15mm, 8mm, Phillips screw driver (or 8mm nut, depending), light to see, a mirror, etc. The 8mm wrench/socket is to remove the ground/strap for sure. When removed, if the brushes are the culprit, it should be apparent as others have suggested.

Removing the ALT is a challenge as well. Right Fan needs to be removed. The AC Compressor needs to be unbolted and dropped down out of the way. The Serp Belt needs to be removed and the Serp tensioner needs to be removed.

Keep us posted!
I apologize for making this confusing for everyone I'm just in a panic. I have had history with alternator issues. Last winter I kept getting an alt light because my fuse melted and I wasn't getting a connection. When my light first came on the other night my first thing to check was that fuse but it was fine. Last night, I was driving home and the lights started to flicker and my car nearly shut-off but then it perked back up a little bit and got me home. My serpentine belt has been making kind of a dry chatter/shutter noise while running. When I shut it down it makes a strange flutters noise which it has never done before. I'm getting to school by fully charging it at night and on a hope and a pray. Yesterday I drove all day with multiple shut downs and start ups and my battery would stay at a consistent 10.5ish but I wasn't monitoring it when it started to die completely. I have bad vibrations in reverse but I believe that is from my shot dogbone bushings because when I park, the engine kind of shifts around and finds a spot where the idle vibrates my interior. I'm basically listing off everything I can. I have a multimeter, I just need to know what to measure besides battery level with car off and on.
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