1957 new alternator drains battery

[vanwormer7]

Replaced generator w/ alternator, one wire hook up to battery. Now it drains Battery over night. Alt is warm to the touch.

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 

[1957Bird]

Have you run the car with any lights or accessories on since you installed the alt.??
If so?? My guess is that there isn’t a satisfactory body ground and lights grounded back through the alternator
And sorry but probably fried it :-(
Assuming that you eliminated the original voltage regulator??
Been there done that:-(

 

[vanwormer7]

Have you run the car with any lights or accessories on since you installed the alt.??
If so?? My guess is that there isn’t a satisfactory body ground and lights grounded back through the alternator
And sorry but probably fried it :-(
Assuming that you eliminated the original voltage regulator??
Been there done that:-(

No to accessories being on. And I did an external ground to the Alt. I did notice a very small spark when I reconnected the battery cable. I just got the car back from the body shop. Thinking that maybe a low amp drain, like a light bulb or switch going to ground somewhere. I am thinking of just doing the slow disconnect of wires or fuses to get the spark turned off. If it was a large spark it could be a solenoid, but it is small. Thanks for you response.

 

[Bebo]

No to accessories being on. And I did an external ground to the Alt. I did notice a very small spark when I reconnected the battery cable. I just got the car back from the body shop. Thinking that maybe a low amp drain, like a light bulb or switch going to ground somewhere. I am thinking of just doing the slow disconnect of wires or fuses to get the spark turned off. If it was a large spark it could be a solenoid, but it is small. Thanks for you response.

With the key/ignition off, disconnect the positive battery cable and connect a circuit tester with alligator clips to the cable and then the positive battery post. The light will be on if there's a drain on the battery. If the light is on, start pulling the fuses one at a time until the light goes off. Once the light goes off you have found the circuit that needs attention.

 

[vanwormer7]

Thanks to all for answering. Now MY CONFESSION. The white wire is not for the battery. It is the IDIOT light wire. That is what I did. In a small way the directions stated red wire goes to the STUD on the Alt and Batt goes to the POST. Stud and post are the same. It works and now I have to fix many other problems, THANKS to ALL.

 

[Tater Salad]

Thanks to all for answering. Now MY CONFESSION. The white wire is not for the battery. It is the IDIOT light wire. That is what I did. In a small way the directions stated red wire goes to the STUD on the Alt and Batt goes to the POST. Stud and post are the same. It works and now I have to fix many other problems, THANKS to ALL.

I am about to connect alternator and fire the car, and am wanting to verify a couple of things.
1. The battery (yellow / black) connects to post with red wire on alternator?
2. What did you ground too?
3. Which wire is from the idiot light? (I know the white will connect to it.)

 

[vanwormer7]

I am about to connect alternator and fire the car, and am wanting to verify a couple of things.
1. The battery (yellow / black) connects to post with red wire on alternator?
2. What did you ground too?
3. Which wire is from the idiot light? (I know the white will connect to it.)

My alternator has a internal voltage regulator. Yes yellow/black is connected to the red post. Mine has a two wire ( red &white) connector below the red post. White is idiot and capped off. Red goes to the red post above it with the yellow/black wire. I did install a ground wire to the alt case for a better ground. It works great. Good Luck!

 

[vanwormer7]

I replied to the message above, Hope you got it. I then noticed post replay here, maybe it is for all to see.

 

[Tater Salad]

My alternator has a internal voltage regulator. Yes yellow/black is connected to the red post. Mine has a two wire ( red &white) connector below the red post. White is idiot and capped off. Red goes to the red post above it with the yellow/black wire. I did install a ground wire to the alt case for a better ground. It works great. Good Luck!

Thanks.
I have same alternator, not gonna ground with wire because it's grounded great to the block and block grounded with battery post and good body ground.
Do you know which wire from the car connects to the white one? For the idiot light. Im leaning toward white with black tracer.

 

[vanwormer7]

Thanks.
I have same alternator, not gonna ground with wire because it's grounded great to the block and block grounded with battery post and good body ground.
Do you know which wire from the car connects to the white one? For the idiot light. Im leaning toward white with black tracer.

 

[vanwormer7]

Looking @ the wiring diagram it is yellow with black stripe. It went to the old reg. that I left on for looks with fake wires.