# Battery / Alternator Issue



## GFT 12:17 (Jul 26, 2014)

My 66 GTO sat for about 2 weeks while on vacation. Once I tried to start it up, my battery was dead. I couldn't even jump it with my daily driver. I had to charge the battery for a few hours and then jump with my wife's suburban. A few days later my battery light comes on while driving, I pulled into an AutoZone and the guy tells me he can't even get a reading on the battery. I was able to restart the car and drive home. Upon further inspection, I noticed the battery wire to my alternator was not connected and you could tell it had arced/sparked. I connected the wire, thinking this was my issue. The car will start, but the battery light comes on whenever the engine is running. Drove to O"Reilly's and they also told me the bad battery is bad and my alternator is fine. I took the battery out of the car and took it to a place that sells AC Delco batteries and they tested it. It tested fine.

With the car running and headlights on, I revved the motor and the highlights brightness didn't change. Turned off the car, brightness remained the same, car started back up.

Could my issue be with the battery wire to the alternator? It wasn't screwed together before, maybe just touching the terminal/screw and then separated. The terminal/screw can be pushed back into the alternator. Is that typical? I would post a picture, but it appears I am unable to do so.

Any suggestions would be appreciated.

Tim


----------



## Lemans guy (Oct 14, 2014)

GFT, sounds like the loose connection was the beginning of something ....

You have to have that connection tight at the red of the alternator, have not seen where it pushes in....

Also the loose connections could have caused some internal diode problem.

Best thing would be to put it on machine that every service station has, called a VAT tester, sometimes it is on a cart...mine is a snap on the size of an iPad

You connect to the battery and one connection to the alternator cable, it puts a micro load on the battery and tests alternator output under load at 2000 RPM,s

It does starter draw as well. This is done without taking the battery or anything out of the car, simple and accurate test....

Now you put a volt meter on the alternator as well and same with the battery but a load test is crucial.

You might have a shorted diode from that loose connection.....but check it.

The alternator is easy to change rebuilds around here $50 bucks.....

You will get it.....:thumbsup:


----------



## PontiacJim (Dec 29, 2012)

Might also be your voltage regulator which should be found on the firewall. The small black box has a set of points in it that do go bad after time. If not working correctly, it will not charge the battery and your light will come on. Then the next time it may work just fine. So it could be a sign that it is going. If your battery checks out OK and your alt checks out OK, then the voltage regulator could be suspect as well. Could be something else, but battery, alt, voltage regulator are your first checks.


----------



## Matthew (Feb 11, 2011)

I agree with Jim on the voltage regulator. Do not replace it with the Duralast VR715 from Autozone.


----------



## GFT 12:17 (Jul 26, 2014)

Bingo, Jed's a millionaire! Replaced the voltage regulator, battery light is out and car is running well. Thanks again for your responses.

Tim


----------

