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Old 12-21-2009, 01:23 PM   #1
wrx03.4wz
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Default What are the signs of a bad Alternator?

OK I have been having starter trouble for the past 4 months now, the battery is a year old and has never died (yet).
Symptoms:
repetitive clutch depressions until start (like 7-10)
license plate lights & dome light flicker @ idle

also the car does have 130,XXX miles on it could it be time to have the alt. switched out?
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Old 12-21-2009, 03:30 PM   #2
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bump status
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Old 12-21-2009, 06:47 PM   #3
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Quote:
What are the signs of a bad Alternator?
the battery light will be on and the battery will die
____________________________

you almost certainly have a bad alternator....but you likely have a bad clutch saftey switch and a bad battery connection and/or terminals and/or bad grounds and/or some other electrical issue

but the alternator isnt likely it
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Old 12-21-2009, 08:03 PM   #4
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the battery light will be on and the battery will die
____________________________

you almost certainly have a bad alternator....but you likely have a bad clutch saftey switch and a bad battery connection and/or terminals and/or bad grounds and/or some other electrical issue

but the alternator isnt likely it
Could he use a multimeter to check the voltages that the alternator is putting out?

If an accessory drive belt/alternator belt was slipping it could cause symptoms like what the OP is experiencing, couldn't it?
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Old 12-21-2009, 08:18 PM   #5
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Could he use a multimeter to check the voltages that the alternator is putting out?

If an accessory drive belt/alternator belt was slipping it could cause symptoms like what the OP is experiencing, couldn't it?
No battery light, and I just replaced the belts 2 weeks ago any tighter I think they would kill somebody.
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Old 12-21-2009, 08:20 PM   #6
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also I just wanted to know what does "OP" stand for?
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Old 12-21-2009, 08:21 PM   #7
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also I just wanted to know what does "OP" stand for?
Original Post or Original Poster.
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Old 12-21-2009, 09:35 PM   #8
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Quote:
Originally Posted by Pinned View Post
Original Post or Original Poster.
I see thanks
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Old 12-21-2009, 10:12 PM   #9
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No battery light, and I just replaced the belts 2 weeks ago any tighter I think they would kill somebody.

and this is a bad idea as it kills bearings

you should be able to twist the belts 90 in the middle of their longest run between pulleys

too tight is madness
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Old 12-21-2009, 11:14 PM   #10
wrx03.4wz
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and this is a bad idea as it kills bearings

you should be able to twist the belts 90 in the middle of their longest run between pulleys

too tight is madness
got it
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Old 12-22-2009, 11:06 AM   #11
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The flickering lights could mean the battery is low on charge or some diodes are bad in the alternator which causes ripple voltage. That is what makes the lights flicker.
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Old 12-22-2009, 02:49 PM   #12
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The flickering lights could mean the battery is low on charge or some diodes are bad in the alternator which causes ripple voltage. That is what makes the lights flicker.

or all the grounds are bad and the terminals are lose and corroded
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Old 12-23-2009, 11:42 AM   #13
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or all the grounds are bad and the terminals are lose and corroded
When grounding is bad it usually causes the lights to just be dim or can cause other strange things to happen when the return side finds a better path back to the battery. If the battery has a low charge due to bad connection to the alternator I could see that causing flickering on the lights. The battery helps absorb the small amount of DC ripple (when the diodes are in good shape) coming from the alternator.
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Old 12-23-2009, 09:34 PM   #14
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Originally Posted by Cougar4 View Post
When grounding is bad it usually causes the lights to just be dim or can cause other strange things to happen when the return side finds a better path back to the battery. If the battery has a low charge due to bad connection to the alternator I could see that causing flickering on the lights. The battery helps absorb the small amount of DC ripple (when the diodes are in good shape) coming from the alternator.

and the 'dimming' may just be the ac compressor coming on at idle and isnt considered by the complaintant because he doesnt have the AC 'ON'

and I am all too well aware of the components of the system and their functions...apparent and otherwise

and ripple is one of the often overlooked diagnostics...............that I dont
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