I have a 2000 Civic. The battery kept dying, so we checked it. It was fine. The next thing, we swapped the alternator out. Alternator is fine. Checked the fuses and they are fine. The problem is when we pull the positive cable, the car dies, which leads us back to the alternator. We are stumped. Any suggestions?

 

welcome to the forum. take the alternator to a shop and have them put it on a load test, ( spin up the alternator ) sometimes a diode goes bad and will not produce the power it is rated to do. so the same for the battery ( load test )

 

Tried that, no luck! Any other suggestions?

 

check to see if you have a draw from the battery when the the car is shut down.
If the Alterntor is good, and the battery is good, your battery should stay charged unless there is something in the system drawing power... courtesy light bulb burnt out but drawing power ( light out ) radio switch off but still drawing power.
try another test. after running the car all day, disconnect the cable and test the voltage should be 12-13 volts. Then check the battery in the morning before you hook up the cable. If it drops, battery bad, If you have less than 12volts after a days run, your alternator is not putting out.

 

Turns out that up underneath the hood, there was a fuse that wasn't marked on the box. It was an alternator fuse. We changed it and it works fine now. Thanks for the help.