Alternator problem
Thread Starter
3rd Gear
Joined: Feb 2006
Posts: 3
Likes: 0
Alternator problem
I've got a 79 L-82 with an alternator problem that I can't figure out.
The dash guage indicated that it wasn;t charging. I checked it at the battery with a meter and it was not. I took the alternator to a shop, they checked it and told me it was ok. I put it back in and checked the wiring. Everything checked out; good ground, voltage at the BAT terminal and the 1 and 2 terminals was ok. I started it up and the guage again indicated it was not charging. I revved it a few times and it suddenly started charging.
Does anyone have any ideas? Is it the internal regulator and if it is how do I check it? Can I buy a regulator? If so, where?
I'm stumped and would appreciate any help from other Vette owners.
The dash guage indicated that it wasn;t charging. I checked it at the battery with a meter and it was not. I took the alternator to a shop, they checked it and told me it was ok. I put it back in and checked the wiring. Everything checked out; good ground, voltage at the BAT terminal and the 1 and 2 terminals was ok. I started it up and the guage again indicated it was not charging. I revved it a few times and it suddenly started charging.
Does anyone have any ideas? Is it the internal regulator and if it is how do I check it? Can I buy a regulator? If so, where?
I'm stumped and would appreciate any help from other Vette owners.
Heel & Toe
Joined: Apr 2005
Posts: 19
Likes: 0
I've seen this before with mine, and I didn't want to think it, but it was the wiring harness. When I was troubleshooting this on mine, I found this article helpful: http://www.misterfixit.com/dedbatt.htm.
If you do choose to do something with the harness or other components, I've bought from a good company I can recommend. Can't remember what the policies are on posting links here to vendors.
If you do choose to do something with the harness or other components, I've bought from a good company I can recommend. Can't remember what the policies are on posting links here to vendors.
Melting Slicks
Joined: Mar 2004
Posts: 3,468
Likes: 18
From: Lake Ozark, MO
Was it showing discharge? Or just in the "neutral" position around 12 Volts? That would be normal if the battery had a good charge. The guage appears to be working if it moved to show a charge.....are the low reading at slow speed or idle? YOu can buy a regulator at any of the chain auto stores...may cost more for that that a remanufactured alternator ...check first.
Drifting
Joined: Nov 2002
Posts: 1,665
Likes: 1
From: Ontario
Its normal for our alternators to not charge with the engine running below 1000 RPM (at night you probably notice your lights dull at idle?)
If you get 14V at the battery positive when you rev the engine above 1200RPM or so you are probably fine.
If you get 14V at the battery positive when you rev the engine above 1200RPM or so you are probably fine.
Melting Slicks
Joined: Aug 2004
Posts: 2,887
Likes: 221
From: Oakbank Manitoba
I had this problem with mine years ago. Turns out the charge wire going from the alternator back to the battery was broken at the junction block mounted in the battery compartment on my 1980 Corvette. The junction block is mounted on the side wall in the battery compartment. Check the connections to it. Mine was cracked and hard to spot the problem.
Intermediate
Joined: Feb 2006
Posts: 36
Likes: 0
if the elec. block is OK, remember the little charging/battery idiot light...must work or it will not charge.
Also check the fusible link at the starter....probably not the problem, but..........if this is not it throw away the alternator and get another one, can we say intermittent.................
Also check the fusible link at the starter....probably not the problem, but..........if this is not it throw away the alternator and get another one, can we say intermittent.................
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Instructor
Joined: Feb 2004
Posts: 126
Likes: 3
From: Bloomingburg NY
I would also check the battery. I had a problem on my 77 that wouldn't charge most times. I noticed when I jumped the car to start it, as soon as it started it was charging. I get out to disconnect the jumper cables and it's no longer charging. Turned out the battery had a loose post and would not accept a charge.