when i start my car it runs, but then it dies when i take off the negative from the battery, so i bought a new alternator and then i did it again and it still died when i took off the negative from the battery... so i changed the fuse box and it is still doing the same thing.. what is wrong with my car? it is a honda civic sir motor.. I know that it is just running from the juice in my battery..

 

Check the pinout on the alternator, odds are the field control circuit is not working. make sure the alternator is hooked up and turning... should be a no brainer.

NEVER remove the negative battery terminal with the car running, you will overheat the diodes in the alternator and ruin it.

 

yea, car still is not running...

 

Like slowcivic2k said...don't remove the negative terminal with the engine on. Check the voltage of the battery with a multimeter.

1. With engine OFF, it should read about 11.5V DC. If not...bad battery.
2. With engine ON, it should read about 14.3V DC. If battery checks OK, you have a bad alternator.