I think that my alternator is about to give up the ghost. I have no charging problems unless I am idling in the pouring rain with both windshield wipers and defogger and radio going for 20 minutes. But when it's cold, I hear a click click from the belt side of the engine, in the back. I only have an alternator and a ac compressor. at idle I get 14.45 volts at the battery, and at 3000 rpms I get 14.5 volts at the battery. Can anyone tell me how else to test it?
Bad Alternator signs
- Thread starter Shaman
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Is the clicking continuous? It could be the bearing going bad. And what happens when you run the defogger, wipers and radio? Does it run down the battery? Is this when you are driving or idling? Are the headlights on also? I would have the battery load tested as well as look at the alternator bearing.
The battery is well within warranty, but the oil change guy said to get it checked. I may try to go by the place I bought it and have it tested. I haven't fully loaded the charging system yet. I will try it at school tomorrow and see what I can come up with.
The noise is only at startup. It has been making it for a week or 3. Goes away unless it's really cold by the time i am out of the neighborhood.
The noise is only at startup. It has been making it for a week or 3. Goes away unless it's really cold by the time i am out of the neighborhood.
The only better testing you can do is to put a load on the alt. with a load tester and see that it keeps up. Headlights, fan, radio, rear defrost can also be used as loads.
If your bring the alt. into a rebuild shop they can test it out, feel the bearing to see if its worn, and replace it if needed for probably much less than a rebuilt.
If your bring the alt. into a rebuild shop they can test it out, feel the bearing to see if its worn, and replace it if needed for probably much less than a rebuilt.
Alternator bearings usually whine or shriek before going belly up.
With the car off, you should have about 12.5V, and running at elevated idle, 14-14.5V or so.
That click may be a bad idler or tensioner pulley.
Take off the belt and check the components by hand.
With the car off, you should have about 12.5V, and running at elevated idle, 14-14.5V or so.
That click may be a bad idler or tensioner pulley.
Take off the belt and check the components by hand.
There is no tensioner. Just the crank pulley, the AC and the alternator. They are adjusted by a bolt I guess. The engine is too tight for me to see. I started the car after sitting for 3 hours, and turned on the front and rear wipers, rear defrost, blower on high, headlights on, everything but the dome light and high beams, and I was getting about 12.35-4 at idle.
This sounds like what is going on with my 99 Buick LeSabre. The headlights are dim at idle, the blinkers are slower when idling, and it's there's a clicking sound all the time at idle that I can't hear as engine speed increases.
If you are only getting 12.4 with eveything on the alternator is on the edge of going. Replace it or have it rebuilt.
As soon as you get things like ABS lights, air bag lights, and dimming lights it's a low voltage condition from a bad alternator tripping all of those, drive it straight to the shop while they might have a chance of just replacing the alternator and not the battery, and save yourself a hundred bucks.
I ended up having that problem and apparently on computer controlled vehicles a bad battery or alternator will show up as all kinds of other electrical errors first.
I ended up having that problem and apparently on computer controlled vehicles a bad battery or alternator will show up as all kinds of other electrical errors first.
The battery already has a warranty, and I will be looking for a new alternator this week. May end up costing a few $100 or so.
Just randomly, would a bad battery have the same signs?
The signs show up under a low voltage condition because the battery doesn't have enough juice to make up the difference for the alternator, take it out on the highway and see if the problem goes away. If it goes away when you run the engine at speed, it's almost certainly the alternator being marginal and at idle it doesn't produce enough charge to keep everything running, so the battery has to prop the whole system up.
Full loads at idle can drop the voltage a lot. Many alternators will not be spinning fast enough to charge properly. Low voltage in those conditions is not a sure sign of a bad alternator.
+1 for mechtech.
Look up the amp ratings at idle and speed. You'll find at idle it's only 40% or so of full output. This is why cop cars also have huge batteries: when they idle all lit up they're at about a "break even" even with their heavy duty alts.
Look up the amp ratings at idle and speed. You'll find at idle it's only 40% or so of full output. This is why cop cars also have huge batteries: when they idle all lit up they're at about a "break even" even with their heavy duty alts.
Originally Posted By: Shaman
I think that my alternator is about to give up the ghost. I have no charging problems unless I am idling in the pouring rain with both windshield wipers and defogger and radio going for 20 minutes. But when it's cold, I hear a click click from the belt side of the engine, in the back. I only have an alternator and a ac compressor. at idle I get 14.45 volts at the battery, and at 3000 rpms I get 14.5 volts at the battery. Can anyone tell me how else to test it?
Sounds like the AC clutch. I would drive it and not worry.
What is the charging problem?
I think that my alternator is about to give up the ghost. I have no charging problems unless I am idling in the pouring rain with both windshield wipers and defogger and radio going for 20 minutes. But when it's cold, I hear a click click from the belt side of the engine, in the back. I only have an alternator and a ac compressor. at idle I get 14.45 volts at the battery, and at 3000 rpms I get 14.5 volts at the battery. Can anyone tell me how else to test it?
Sounds like the AC clutch. I would drive it and not worry.
What is the charging problem?
How is the AC clutch a problem?
There is no charging problem persay, just the recommendation at the “garage” to get the battery checked, and the random clicking heard lately led me to believe that the alt was going out. The lights dim when the engine shuts off, and the rpms change when I turn on a big power drawer, like the lights or the engine fan.
There is no charging problem persay, just the recommendation at the “garage” to get the battery checked, and the random clicking heard lately led me to believe that the alt was going out. The lights dim when the engine shuts off, and the rpms change when I turn on a big power drawer, like the lights or the engine fan.
After a drive and with all accessories off, what voltage does the battery measure with the engine on and off?
I will check that on the way to autobacs. It's looking like $150 for used and $300 for a new alternator.
For that price, the alternator from AZ could probably be shipped to me.
For that price, the alternator from AZ could probably be shipped to me.
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Okay, after driving home. Everything off. 14.48, and 14.49 with the door closed. Engine off 13.55, counting down to 12.51
The voltage continuing to drop from 13.5 to 12.5 after shut-off seems to suggest that the battery isn't holding a charge or that you have large parasitic losses. So don't condemn the alternator just yet.
What's the voltage at the battery after sitting overnight? How's the electrolyte level? How long ago did you get this battery? How long have you noticed a problem? Seems you only suspected a problem when you heard the ticking?
What's the voltage at the battery after sitting overnight? How's the electrolyte level? How long ago did you get this battery? How long have you noticed a problem? Seems you only suspected a problem when you heard the ticking?
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