Charging Issue- 1978
Thread Starter
Instructor
Joined: Feb 2005
Posts: 169
Likes: 3
From: New Jersey
Charging Issue- 1978
My 78 is not charging. I checked the 2 wire plug on the alternator with the ignition on (but not running) and have 12V on the red but no voltage on the brown wire. The "gauges" fuse looks good. What to check next?? 
TIA!
Ed
TIA!
Ed
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
Look at the back of the alternator. You will see a D shaped hole with a small tab in it. Take a small screwdriver and short that tab to the case. If it charges, the problem is with the regulator.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Try this. Turn the key to on,unplug the 2 wire connector at the alt,use a little piece of wire and ground the brown wire. If the light comes on in the dash you have internal problems in the alt ,probably as Wombvette said in the regulator.
Thread Starter
Instructor
Joined: Feb 2005
Posts: 169
Likes: 3
From: New Jersey
I grounded the brown wire to the alt: no light. The alt is not very old.
Roger- from researching other posts on this topic, I thought there shoud be 12v on the brown wire without the car running (exciter wire).
Will swap out the alt and see, Thanks for this input.
Roger- from researching other posts on this topic, I thought there shoud be 12v on the brown wire without the car running (exciter wire).
Will swap out the alt and see, Thanks for this input.
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Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Just a guess but I'm thinking the large plug in the back of the center gauge cluster is shorted across in the printed circuit.
You might get away by removing the cluster,pulling the plug out of the back,then straighten the fragile printed circuit fingers,glue them down and reinstall the plug.
Thread Starter
Instructor
Joined: Feb 2005
Posts: 169
Likes: 3
From: New Jersey
One of the curcuit board fingers was munched up- sloppy hook up by whomever did the radio install. All good now.
Thanks Roger!
Thanks Roger!
Last edited by EWJ; Jun 11, 2011 at 03:06 PM. Reason: spelling
2nd Gear
Joined: Jun 2011
Posts: 2
Likes: 0
Help!!
I also have a 1978 silver anniversary vette. Alternator went bad and have replaced it now getting 12 volts when the car is off and 14.7 volt charging but Gen Light still comes on all of the gauges in the dash dont work. Any advice would be a great help on where to start.
Thanks,
silver25vette.
Thanks,
silver25vette.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
2nd Gear
Joined: Jun 2011
Posts: 2
Likes: 0
Before I tear into the dash though.... and with every gauge not working including speedometer and rpms, and now the headlight buzzer/alarm goes off when I turn the headlights on,
could there be a short else where?
Silver25Vette
could there be a short else where?
Silver25Vette
