'76 Alternator Regulator / Battery problem (1st post!)
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Joined: Sep 2008
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From: Iowa
'76 Alternator Regulator / Battery problem (1st post!)
I just bought a '76 L-48 as a project car and everything runs fine except for the charging system. Listed below are the problems I'm experiencing and what I've tried to do to solve them - any tips or advice is greatly appreciated!
-The battery was be completely dead after the car has been shut off for a few hours. Jumping the car allowed it to start and recharge the battery while driving. No driving problems. After the car has been shut off it can be started for about the next 30 min - 1 hour. After a few hours, the battery goes dead again.
-At this point, I went to my local auto parts store and they tested my system. The alternator is charging (although only 12.9volts, which the serviceman said was ok for a car this age) and he recommended replacing the battery. So I replaced the battery. Car started right up and I drove home.
-Next morning the new battery was completely dead. A friend said the regulator may be bad in the alternator and that this could run the battery dead. I pulled out the old alternator and went back to the auto parts store and got a remanufactured one.
-Here is the interesting part. After installing the new alternator, I tried to start the car (fully charged battery) and the car would not turn over. It would "chug" a few times and not start. Finally, after coaxing it for a few minutes the car started. My wife did point out to me that she briefly saw sparks in the alternator during this process. I don't know if it was supposed to do that.
I drove the car to work later in the day and when I left (about 8 hours later) the battery was dead again. I had someone jump the car again and it started and drove just fine. After I got home, I went ahead and pulled the battery out and put it on the charger again, and pulled the new alternator out. I will be getting a replacement alternator just in case.
My question is, how do I fix this charging problem, and what could the potential culprits be? I am new to working on Corvettes as this is my first project (I used to be a Buick guy.) Thanks!
-The battery was be completely dead after the car has been shut off for a few hours. Jumping the car allowed it to start and recharge the battery while driving. No driving problems. After the car has been shut off it can be started for about the next 30 min - 1 hour. After a few hours, the battery goes dead again.
-At this point, I went to my local auto parts store and they tested my system. The alternator is charging (although only 12.9volts, which the serviceman said was ok for a car this age) and he recommended replacing the battery. So I replaced the battery. Car started right up and I drove home.
-Next morning the new battery was completely dead. A friend said the regulator may be bad in the alternator and that this could run the battery dead. I pulled out the old alternator and went back to the auto parts store and got a remanufactured one.
-Here is the interesting part. After installing the new alternator, I tried to start the car (fully charged battery) and the car would not turn over. It would "chug" a few times and not start. Finally, after coaxing it for a few minutes the car started. My wife did point out to me that she briefly saw sparks in the alternator during this process. I don't know if it was supposed to do that.
I drove the car to work later in the day and when I left (about 8 hours later) the battery was dead again. I had someone jump the car again and it started and drove just fine. After I got home, I went ahead and pulled the battery out and put it on the charger again, and pulled the new alternator out. I will be getting a replacement alternator just in case.
My question is, how do I fix this charging problem, and what could the potential culprits be? I am new to working on Corvettes as this is my first project (I used to be a Buick guy.) Thanks!
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Joined: Dec 2007
Posts: 128
Likes: 1
From: Gulfport Ms.
The alternator should not spark, but there may be something draining the system as well.
With the car and all accessories off, remove a battery cable and connect a test light between the battery post and cable. If the light comes on, something is pulling current.
With the car and all accessories off, remove a battery cable and connect a test light between the battery post and cable. If the light comes on, something is pulling current.
