Still having electrical problem, HELP ! !
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,753
From: Charlotte NC
69Vett,
DO NOT stop trying to assist people who are asking for help.
BACK to your advice. He has the charging system that has the power wire that attaches to a junction block in the battery box....and that wire runs IN the frame in a section of plastic split loom...and goes to the alternator. That wire should have power on it.
I looked in my 1980 manual and it does not show that design...but I know a 1981 and 1982 has it...I just need to look at it and see what is going on.
DUB
DO NOT stop trying to assist people who are asking for help.
BACK to your advice. He has the charging system that has the power wire that attaches to a junction block in the battery box....and that wire runs IN the frame in a section of plastic split loom...and goes to the alternator. That wire should have power on it.
I looked in my 1980 manual and it does not show that design...but I know a 1981 and 1982 has it...I just need to look at it and see what is going on.
DUB
Thread Starter
Racer
Joined: Jan 2009
Posts: 462
Likes: 1
From: Westernport Maryland
Replaced alternator with 3-wire alt and the main ground. The old ground was copper clad aluminum that had turned to powder. Guess what, nothing changed. I am about to hang it up.
Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
yes very much so, your problem may be in the 50 year old positive cable,
the connections, they may look fine, but looks don't conduct electricity.
However if that positive cable is the problem, it would show up with starting problems ?
good luck.
the connections, they may look fine, but looks don't conduct electricity.
However if that positive cable is the problem, it would show up with starting problems ?
good luck.
Last edited by 69Vett; Aug 21, 2014 at 03:50 PM.
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
Put a new ground cable in it.......the one to the frame from the battery.....I believe you have a automatic and the ground is going through your shift cable....a white powder on the cable suggests the ground is no good
One wire alts are not a good answer to your charging system problems....a 120 A alternator is not correct for a 1980 Vette nor is a one wire
One wire alts are not a good answer to your charging system problems....a 120 A alternator is not correct for a 1980 Vette nor is a one wire
Thread Starter
Racer
Joined: Jan 2009
Posts: 462
Likes: 1
From: Westernport Maryland
Here's the latest.
New 120 amp. alternator, new main ground, new starter to battery cable. New charge wire. Still won't charge, 12.8 v on gauge.
Does any one know "all" the ground points? That is the only thing left I can try.
Does any one know "all" the ground points? That is the only thing left I can try.
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,559
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From: New Or-leens Loo-z-anna
On my vehicle I upgraded to a 130 amp alternator.
A constantly "Hot" thick gauge wire goes to the large BATT lug on the back of the alternator.
A thick ground wire can be run from the alternator case mounting bolt to a clean area on the frame.
The thick wire that comes out of the plug-in connector for the alternator should go to a positive wire that is HOT when the engine is running,
The smaller gauge wire coming out of the connector should go to a separate bulb connection.....the other wire that comes out of the bulb connection should be run to a fuse that supplies 12volts ONLY when the key is turned to the ON position (This "bulb connection" is the "exciter" that causes the alternator to start producing 13 to 15 volts when the engine is started....Rev the engine a couple times to excite the alternator). Running a 12 volt wire straight to the alternator will cause the alternator to "burn out" in a month. The bulb set-up MUST be wired into the connector to prevent burn-out.
Google GM 3-wire diagrams to get a good idea of how the wiring should be connected .
A constantly "Hot" thick gauge wire goes to the large BATT lug on the back of the alternator.
A thick ground wire can be run from the alternator case mounting bolt to a clean area on the frame.
The thick wire that comes out of the plug-in connector for the alternator should go to a positive wire that is HOT when the engine is running,
The smaller gauge wire coming out of the connector should go to a separate bulb connection.....the other wire that comes out of the bulb connection should be run to a fuse that supplies 12volts ONLY when the key is turned to the ON position (This "bulb connection" is the "exciter" that causes the alternator to start producing 13 to 15 volts when the engine is started....Rev the engine a couple times to excite the alternator). Running a 12 volt wire straight to the alternator will cause the alternator to "burn out" in a month. The bulb set-up MUST be wired into the connector to prevent burn-out.
Google GM 3-wire diagrams to get a good idea of how the wiring should be connected .
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2026 Loser of the Year
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From: New Or-leens Loo-z-anna
Yes the Idiot light excites the alternator into producing adequate voltage.
Here is a simplified diagram of the system.....this diagram shows the slightly larger wire in the connector being connected at the BATT+ lug on the back of the alternator,......However, I have read that the farther away from the alternator that this wire is connected to a positive 12 volt source, the better the alternator will keep the battery charge.
You could try using the diagram "as is" just to simplify the wiring because your main objective is to get the alternator charging adequately in the first place
I wish I could be more help, but Ive only connected two three-wire alternaotrs......
I could take a pic of the upgraded '68 Vette alternator wiring if it would help you more
Here is a simplified diagram of the system.....this diagram shows the slightly larger wire in the connector being connected at the BATT+ lug on the back of the alternator,......However, I have read that the farther away from the alternator that this wire is connected to a positive 12 volt source, the better the alternator will keep the battery charge.
You could try using the diagram "as is" just to simplify the wiring because your main objective is to get the alternator charging adequately in the first place
I wish I could be more help, but Ive only connected two three-wire alternaotrs......
I could take a pic of the upgraded '68 Vette alternator wiring if it would help you more
Thread Starter
Racer
Joined: Jan 2009
Posts: 462
Likes: 1
From: Westernport Maryland
Problem fixed - update
Well the charging issue is resolved, BUT I don't know what fixed the problem. I noticed the belts weren't right. Crank, WP, alt. PS and AC only to WP. Got the right belt for AC and also a new one for alt. I installed the belts, tensioned them, started the engine to check if they needed re-tensioned, it was charging. Original install of the alt. I broke the chrome where the mounting bolt passes through with a file to make contact, did not do anything but the belts and it charges. Hate when something fixes it self and I don't know what he fix was.
Last edited by dpw21562; Jun 1, 2015 at 12:38 AM.
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
Well the charging issue is resolved, BUT I don't know what fixed the problem. I noticed the belts weren't right. Crank, WP, alt. PS and AC only to WP. Got the right belt for AC and also a new one for alt. I installed the belts, tensioned them, started the engine to check if they needed re-tensioned, it was charging. Original install of the alt. I broke the chrome with a file to make contact, did not do anything but the belts and it charges. Hate when something fixes it self and I don't know what he fix was.
Are you saying the alternator pulley is/was chrome plated? If so I suggest sandblasting the belt surfaces until the slippery chrome plating is gone or at least until it is dulled. The belt should take about 25 pounds or downward pressure to deflect it 1/2" in the middle.