Are these signs of a dying Alternator?

[DarkStryder360]

I had hazards on with the interior light on. The int' light was dimming each time the hazard flashed.

Having the interior light on, I turned the normal head lights on, the interior light dimmed.

Some times when I start the engine, I hear a supercharger style whine, low to high pitch sound.

Also, the fact the engine doesnt idol correctly (or at all) which was discussed in a previous "car cuts out randomly" thread.

What are other signs of a dying alternator, or if they all arent in the first place, what would be?

Edited April 12, 2010 by DarkStryder360

[Mike_M]

Have you tested the battery with a voltmeter......with the car off and then running?

[DarkStryder360]

Nope haven't touched it as my dad was adamant that 'new' batteries wouldn't fail so soon =/

[Silver!]

Mine was fine until it failed. It started and ran fine after sitting idle for about a month, then the dashboard beeped at me 3 times. All warning lights came on on the dash then the headlights failed leaving sides. Then it beeped again and the binnacle lights and stereo went out.

Pulled over and turned off all electrics. Engine ran fine. Turned on main lights and only one Xenon came on (which truly worried me). ONly side lights were working so I limped home with the dash beeping at me every couiple of minutes.

Battery although not enough power to start the car was showing 12+V, but when I jumped the car and tested again the alternator was only putting out 9V.

About a week later the car started with no jump, but once the electronics pulled what power was left in the battery the dash beeped, then the engine struggled to fire and it eventually died.

New alternator and all has been fine since.

[Mike_M]

Mine failed after 4 years........also testing the battery with a voltmeter before and during the engine running allows you see if it is the battery or the alternator at fault.

About 12V when the engine has been off for a while means the battery is fine and with the engine running the reading should jump above 14V........if it does the alternator is fine, otherwise it is at fault

[Silver!]

Nope haven't touched it as my dad was adamant that 'new' batteries wouldn't fail so soon =/

Tested with the engine running will show you what the alternator is putting out.

[rh203]

Hi, I started the "car cuts out randomly" thread. Just had mine fixed. Had a new alternator fitted, which I believe when it was, the teaser wire going to the alternator was crushed and was causing it to cut out. I also had a new fuse box fitted ( small one where the battery would go in the engine bay) as this was shorting out and had badly corroded points.

When my alternator went initially, the interior lights were dimming and eventually flickered until everything went off.

The aa guy tested it with a multimeter and it showed to be dead.

Now its fixed and my aircon has miraculously started working too :s

[DarkStryder360]

Cheers for all the messages.

Had the Alternator tested yesterday giving, as read above, 12v off, and around 15v when on.

Tested the battery at Halfords, it came up 'unserviceable' meaning dead (to an extent)? Thinking a new 440 amp?