Alternator problems [CL9] - fix or replace?

Just wondering if anyone can help me diagnose this problem

1. Alternator is starting to make a audible whining type noise
2. Seems to increase in pitch and volume when engine revs
3. Battery symbol on dash display comes up to indicate that battery is not charging
4. When I unplug the battery cable from the alternator both the noise and battery symbol disappears
5. Checked the serpentine belt and all looks ok. No slippage, no belt problems.

So my tentative conclusion is that the alternator is gone (car has done around 130,000kms). Can anyone confirm this based on the symptoms I've described?

And also what are my options? Replace or try to fix? I hear that sometimes the bearing in the alternator goes or maybe some other part within the alternator.

Half the time when they "recondition" and alternator they only replace the brushes, but everything on an alternator that wears is more or less replaceable.

Loosen the belt and spin the alternator with your hand if the bearing is going it will most likely feel rough. You will need or improvise a press to replace the rear bearing.

If you get a reconditioned unit make sure it has the correct pulley.

^^ Exactly. Usually it's the bearing behind the pulley that causes the whine.Easier to just swap the whole alternator out but they maybe a bit expensive for your car..unsure.

Quote:

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Originally Posted by MMT

4. When I unplug the battery cable from the alternator both the noise and battery symbol disappears

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From this one, it seems like the whine is an electrical whine and not mechanical (bearing noise).

It is possible that the alternator is cactus where a replacement needs to be done. An auto electrician will confirm this quickly. I think the engine light already told you this.
Something you could do quickly is to check the ground wires.
There are three in CL9 and all very short.
1. the thick wire from the body to the battery. Sometimes this is a little corroded and need replacement.
2. braided wire under the air filter box and
3. another braided wire on the other side near the right engine mount / abs unit.

The alternator is grounded through the engine which connects to both braided wires. If there are different voltages going through these wires (different electrical resistance because of corrosion, etc...) you may get this whining noise. As I said above, it is very possible that the electrical system in the alternator is cactus.
My suggestion is to have a look at all grounding wires and replace them if it is sus.

Have you actually tested the voltage the alternator is putting out?
Check voltage on battery with car off, turn car on and see what its putting out. You want something north of 13 volts or the alternator isn't putting out enough charge. I think its a 12.7 volts and you want have enough charge coming out of the alternator to keep the car alive. I.e. the car will consume more juice than the alternator can make.

Including fitting NRMA charges for an alternator for a CL9 is $531.

Thanks everyone for the comments and helpful tips!

In the end I got the mechanic to have a look and he was confident that the alternator needed replacing. He stated that these days it's easier to just replace the alternator than to try and get it fixed which he said will end up costing be about the same as a replacement. I shopped around and found out that OEM alternators cost around $1200 while after market Alternators (OEX and Bosch) cost around $450 brand new. One auto electrician tried to charge me 1000 bucks for an OEX! LOL! Ebay have OEM ones for around $250-350. I managed to get a recon one off Ebay for $140 and installed it myself. It was a bit of a pain in the @ss to get to but with some fiddling around and some patience and help from a youtube clip it was done. It's been almost 2 weeks now and so far everything is working fine! Fingers crossed!!

$140 is a good price.

My reco'd alternators all involved handing in the old one so that the shop can recondition it. It's like having your own reconditioned, without the wait.

$140 is a really good price for a reco.

I've this whinning sound like u MMT. How long does your alternator start playing up from the start of making that whinning sound? Do you have the model number for the OME or the an aftermarket alternator? I think I will need to get one before it really dies please.

Is the recon alternator still good? I found this and it's supposed to be new genuine honda alternator. Is this too good to be true?

http://www.ebay.com.au/itm/Honda-Acc...4AAOSwc49Y7BCr

looks good to me.