Alternator Question

[peng155]

Hi folks....

Can someone please explain how the battery, and charging system is suppose to work when operating properly??

I have a 71, which I have modified the charging system. I've replaced the orginal generator/external votage regulator setup with the GM Delco alternator setup.

I've had the setup installed, and running in the car for the last year or so, and everything seems to be operating normally.

What I've noticed is the following when driving... With any accessory on at idle the amp meter is at Zero, No discharge, no charge on the system, But once I rev the engine up I see the amp meter needle move to the positive side of the gage, meaning that the system is receiving a charge from the alternator, and the amp meter needle gradually moves from the plus side, back to center, or Zero charge.

Can someone tell me if this is the correct operation of the alternator/battery system?? Also should I reduce the pullie size on the alternator so that the alternator output is higher at idle??

Thanks for your input.....

-Phil

[SteveJ]

The gauge in our 240Zs is an AMP gauge(current). Think about current like the flow of water. As the engine turns the alternator faster, the alternator is able to pump out more current. That's why the gauge goes to the plus side. As it returns to idle, the alternator isn't pumping out as much current. As long as you're not on the negative side, you're in good shape.