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[jay99]

Hello again

I've had a problem in the past few weeks where my battery keeps on going flat, I have replaced it twice and this time I have used a 70ah GM large battery. It still continues to go flat.

When the car starts by either push starting or jump starting it, it runs fine and all the lights, aircon and everything operates, so I presume the alternator does work. But it does not seem like it is charging the battery.

It is being driven by the belt, but there seems to be a loud whining noise emanating from somewhere. It increases when accelerating and I think it is coming from the engine bay. Could this be the alternator?

It obviously is charging when the car is switched on, or else nothing would work, but not enough that it would allow for a crank when I want to start it.


If these symptoms are the alternator, how much would one cost and how much would it cost fitting, is it a difficult job and can a second hand one be used?


Thank you
Jay

2000 facelift 2.0 manual GLS

[mickyboy123]

sounds like the belt may be sliping, failing that i would put my money on the altanator, it would all work fine if the alternator wasnt charging untill battery went flat

[RobG]

Run through these tests first
http://www.omegaowners.com/forum/index.php?topic=90619.0

PS. Alternator is a doddle on the 4-pot

[martin42]

Always get alternator tested first.......

[jay99]

Thank you but that guide looks a little too complicated for me  Just had a look for a multimeter from maplins and £35 

I definitely don't think this is a battery problem. The belt is turning the alternator spinner thing but putting my ear near it now there is a whine, which increases and decreases with acceleration and deceleration.

So like is there a cheap fix, the 70 amp alternators are cheaper than the 100 amp, does this matter

Which alternator shall I go for, there are so many makes and models,

If I buy used, is this a good idea?


And is it simply a case of removing belt, taking it out, replacing it by plugging it in and replacing belt?

Thank you


By the way could it be earthing?

[tigers_gonads]

Take the car down to the local kwick fit and ask them to check the alternator is charging then report back on here 

[Nick W]

Checking the alternator output is easy.
Replacing an alternator without checking it first is foolish hopeful thinking rather than proper diagnosis.
You only need a cheap multimeter for most car related jobs, so keep looking until you find one that is around the £10 level.
I wouldn't fit a lower rated alternator to anything, let alone a modern car.
Nor would I got for a used one unless it was very cheap and I could test it before buying it.

And yes, you do just remove it, fit the new one and check it's working.

[Andy B]

Ask a local autospark to check the output from the alternator ........... I'm surprised that the place that sold you your batteries didn't check alternator output for you. As Nick says, a £10 multimeter from Machine Mart would be good enough to see what voltage is across your battery when the engine is running and will have various other uses on & around your car. 

[Kevin Wood]

Agreed, you do need to make some measurements.

Also, note that car electrical items working do not prove anything. If the alternator has died they will continue to work as usual using battery power - until the battery is flat.

[Entwood]

Stick your location in your profile ... or tell us where you live, there may well be an OOFer nearby who can use a multimeter and can help with an ACCURATE diagnosis...

[jay99]

Thanks for your replies, my location is in my signature  (Oldham)

Tomorrow at 8:30 I have an appointment with a scary man at Kwik fit to check my alternator. Not sure about the test and run as I will feel awful for not buying anything.

I understand that the instruments lights etc will continue to run if he battery is flat. But it is completely flat. Say I have the aircon on with he ignition on and it is very weak, when push started it comes in full power. The green light on the battery is gone and the central locking is weak, the battery is almost completely nearly flat.

I have deduced (big word) that the alternator is working in some capacity as everything improves when the engine running, he lights brighten etc.

Wouldnt the battery light on the dash come on if the alternator failed?

So the alternator must be working, but it is not charging the battery either due to some component failing within the alternator preventing the charge of battery (which may be linked to the whine) or the earthing fault etc.

Sorry for the long rant but all will be well when I get this tested tomorrow. I think the guy is expecting me to buy something but the awfulness won't go away due to my overbearing politeness.

Anyway thank you for your help and I will post the result