What is your voltage gauge showing when the engine is running?
Possible bad alternator?
Thread Starter
Melting Slicks
Joined: Jan 2010
Posts: 2,024
Likes: 4
From: Austin TX
Possible bad alternator?
Alright, so. The day after I bought my 'vette (1-7-10) I had to replace the battery because it was having trouble keeping charge and starting. Right before it died, the dash would flicker and go really dim at night. It did that again tonight, and I'm afraid my alternator is going bad. Could someone tell me if this is possibly the issue before I take it in to get it tested?
Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
The alternator could definitely be at fault. Removing it and having it tested is quick, easy, and free...I wouldn't give it a second thought, just do it. I'm assuming all battery cables are good, solid, and tight....no corrosion. Ground straps are the same.
Slingshot
Joined: Dec 2001
Posts: 3,817
Likes: 24
From: Charlotte NC
I have an alternator off of an 87 Vette with about 8000 miles on it that is in excellent condition and works great. I can let you have for $60 if you are interested. Let me know if this might help you out.
Thread Starter
Melting Slicks
Joined: Jan 2010
Posts: 2,024
Likes: 4
From: Austin TX
Yeah, I think I'll be needing that alternator. Seems my top voltage since this post has been 13.7. I'll get it tested at Autozone tomorrow and let you know.
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Pro
Joined: Oct 2003
Posts: 506
Likes: 12
From: Savannah GA
If you buy an alternator ONLY get a lifetieme warranty.
Ask me how I know?
My 87, I've had for 15years has had 5 I know in it's life. I paid for 1
The #1 cause is heat. With no engine driven fan and factory tune the fan hardly ever comes on so you get no air flow over that cheap CS130 alternator.
All the auto electric people I've talked to say 3,4 yrs is good.
Keep your battery charged up. Will help the diode bridge. Also if you have the boost fan out front you can get a new temp switch for the head for about $20. Mine turns on the boost fan at 200F. Run the AC at 60 the main fan runs a lot. (or is that just adding insult to injury?)
Get the fan temp lowered in a new tune.
JS
The pepboys alternator I bought in 95 was rebuilt. The two replacements were brand new aftermarket units. I'm convinced the last new one was killed by low battery because the vette was under the cover for a month sometimes while was on the road.
Ask me how I know?
My 87, I've had for 15years has had 5 I know in it's life. I paid for 1
The #1 cause is heat. With no engine driven fan and factory tune the fan hardly ever comes on so you get no air flow over that cheap CS130 alternator.
All the auto electric people I've talked to say 3,4 yrs is good.
Keep your battery charged up. Will help the diode bridge. Also if you have the boost fan out front you can get a new temp switch for the head for about $20. Mine turns on the boost fan at 200F. Run the AC at 60 the main fan runs a lot. (or is that just adding insult to injury?)
Get the fan temp lowered in a new tune.
JS
The pepboys alternator I bought in 95 was rebuilt. The two replacements were brand new aftermarket units. I'm convinced the last new one was killed by low battery because the vette was under the cover for a month sometimes while was on the road.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
The factory alternators are just too small. I upgraded to an alternator off of a 92 LT-1 corvette.
I went from 105 amps to 140 amps. the other thing is it's bigger, and there are more stator windings, and it charges at a higher voltage at idle.
it's easy to change, but you have some stuff to do before it's all said and done.
I went from 105 amps to 140 amps. the other thing is it's bigger, and there are more stator windings, and it charges at a higher voltage at idle.
it's easy to change, but you have some stuff to do before it's all said and done.
Thread Starter
Melting Slicks
Joined: Jan 2010
Posts: 2,024
Likes: 4
From: Austin TX
http://www.youtube.com/watch?v=5C35IM7q9Ig
This is my digidash at night. See my problem? The battery is new, bought 1-7-10. The stereo stays fully lit.
This is my digidash at night. See my problem? The battery is new, bought 1-7-10. The stereo stays fully lit.
Last edited by Azriel; Mar 7, 2010 at 03:22 PM. Reason: Wrong link.
Thread Starter
Melting Slicks
Joined: Jan 2010
Posts: 2,024
Likes: 4
From: Austin TX
K, so. I'm not so sure it's the alternator, but what do I know? The headlights maintain brightness, as does the CD player. The dash, however, will dim seemingly only at night. My lowest battery voltage through the day seemed to be 13 'til night where it dropped to 12. The dash seemed normal brightness all day, but then at night it dropped back do being dim again. I've no idea if it's the alternator, or if the dash could be at fault?
Le Mans Master
Joined: Jan 2003
Posts: 5,858
Likes: 7
From: Santa Maria CA
Make sure you're disonnecting your battery during this. That thick red wire bolted to the back of the alternator is hot at all times since it comes directly from the battery's positive terminal. If the metal eyelet of it touches anything metal on the motor you're going to have sparks and a short.
