Alternator bad? or battery? or ground?

**96z28** · 08-17-2008, 02:48 PM

Sometimes after starting my car i notice the battery gauge is fluctuating and i can see my headlights slighty flickering. Sometimes it says like that for the whole comute but somtimes it stops. Any ideas?

**iam_dale** · 08-17-2008, 02:57 PM

check your terminals and such, but my guess is the brushes in the alternator may be starting to go.

dale

**Street Fighter** · 08-18-2008, 04:06 AM

Check the cables and battery postes, make sure they are clean, if it still does it check the starter wires and make sure they to are tight, I it still does it, unless you have a battery tester you will need to take it to Auto Zone or some place that can test the charging system, hopefully for free.

**sunsetorangess** · 08-18-2008, 08:04 AM

Originally Posted by Street Fighter

Check the cables and battery postes, make sure they are clean, if it still does it check the starter wires and make sure they to are tight, I it still does it, unless you have a battery tester you will need to take it to Auto Zone or some place that can test the charging system, hopefully for free.

I agree....
J

**yzfr62k1** · 08-18-2008, 08:50 PM

I have seen the lights flicker a lot in my 98 z28 lately , its random and doesnt always happen.I had the started replaced a while ago and dont know if this has anything to do with it.sometimes the car does not start on the first or second turn of the ignition.

Last night my check gages light came on flickering at first and then steady and I looked a tthe gages and my battery gage was going back and forth from the red zone to the middle. I started the car again today and drove around 3 miles and the battery gage went down all the way to bottom and the car wouldnt start after i turned it off . I had to jump start it and the gage was steadly going lower into the red zone and now the car wouldnt start again.

Im guessing its either the battery or the alternator , does anyone have any thoughts on this ?

Also if I had to replace the alternator , any suggestions on what to buy and how much work it is to replace it ?

Ive been trying to find instructions on replacing the alternator without much luck.

Thanks in advance for any assistance.
yzfr62k1

**96z28** · 08-18-2008, 08:52 PM

Ill probably end up getting a new alternator and battery and clean up the cables and grounds

**TexasLS1** · 08-18-2008, 09:45 PM

Originally Posted by Street Fighter

Check the cables and battery postes, make sure they are clean, if it still does it check the starter wires and make sure they to are tight, I it still does it, unless you have a battery tester you will need to take it to Auto Zone or some place that can test the charging system, hopefully for free.

I'd definetly take the battery and alternator in to AutoZone. They will test them both in or off the car for free. It's much better, and cheaper, to track down the problem than swap out parts and guess in hopes that something works.

**SVG210** · 08-19-2008, 06:32 AM

Originally Posted by yzfr62k1

I have seen the lights flicker a lot in my 98 z28 lately , its random and doesnt always happen.I had the started replaced a while ago and dont know if this has anything to do with it.sometimes the car does not start on the first or second turn of the ignition.

Last night my check gages light came on flickering at first and then steady and I looked a tthe gages and my battery gage was going back and forth from the red zone to the middle. I started the car again today and drove around 3 miles and the battery gage went down all the way to bottom and the car wouldnt start after i turned it off . I had to jump start it and the gage was steadly going lower into the red zone and now the car wouldnt start again.

Im guessing its either the battery or the alternator , does anyone have any thoughts on this ?

Also if I had to replace the alternator , any suggestions on what to buy and how much work it is to replace it ?

Ive been trying to find instructions on replacing the alternator without much luck.

Thanks in advance for any assistance.
yzfr62k1

that sound like an alternator problem, because if it was the battery your car wouldnt be starting, but as you've said that it does that while running then the Alt is not generating properly. I had a similar problem, but it turned out to be my positive post on the battery, when I took it out i saw that it had a bunch of corrission on it so I cleaned it up with baking soda, and water.

**mrr23** · 08-20-2008, 05:44 AM

it'll be your alternator. just got finished replacing mine for that exact same condition.

replacing the alternator will require these tools

5/16" wrench - to disconnect the positive battery cable from battery
15mm wrench - to remove the belt by moving the tensioner. slip belt off the water pump first
15mm socket - remove the three long bolts 2 through alternator 1 through the bracket
13mm wrench - remove the bolt on the rear of the alternator
12mm socket - remove the nut that holds the main cable to the back of the alternator
flat screwdriver - to lift and release the exciter wire connector on the top of the alternator

the fourth one is tricky. there isn't much lead wire. once you remove the four bolts and get the bracket out of the way, turn the alternator around to get a good reach to the exciter wire. pop it out of the alternator, then lower the alternator out of the car from the bottom.

**SVG210** · 08-20-2008, 04:17 PM

Originally Posted by mrr23

it'll be your alternator. just got finished replacing mine for that exact same condition.

replacing the alternator will require these tools

5/16" wrench - to disconnect the positive battery cable from battery
15mm wrench - to remove the belt by moving the tensioner. slip belt off the water pump first
15mm socket - remove the three long bolts 2 through alternator 1 through the bracket
13mm wrench - remove the bolt on the rear of the alternator
12mm socket - remove the nut that holds the main cable to the back of the alternator
flat screwdriver - to lift and release the exciter wire connector on the top of the alternator

the fourth one is tricky. there isn't much lead wire. once you remove the four bolts and get the bracket out of the way, turn the alternator around to get a good reach to the exciter wire. pop it out of the alternator, then lower the alternator out of the car from the bottom.

wow you did yours thru the top? OMG dude you rule!, I had a hell of a switching belts, I could imagine doing an alternator.

**mrr23** · 08-20-2008, 06:49 PM

Originally Posted by hurraquio

wow you did yours thru the top? OMG dude you rule!, I had a hell of a switching belts, I could imagine doing an alternator.

um no. except for belt and battery cable, all is done from the bottom.

**DaddySS** · 08-21-2008, 02:01 AM

Originally Posted by 96z28

Ill probably end up getting a new alternator and battery and clean up the cables and grounds

Unless you just want to throw money away, why not take a few minutes to thoroughly clean the battery terminals and grounds and check the connections.

Lights flickering are fairly common and if it is not the connections then a good alternator shop will rebuild the alternator and replace the diodes (the main cause if not the connections). There are many threads where folks have replaced the alternator and battery and not solved the problem because the specs and tolerances of the off the shelf units are not very good.

How old is the battery?