Join Date: Sep 2008
Location: Fruitland Park,Florida
Moved to lt1 engine section.
First off, what does your vol gauge read with engine running? Should be 13.0 volts to about 14.5 volts. If reading is lower than 12.8 with engine running, alternator is not charging battery enough.
2nd, once engine starts ans alt takes over, bad battery does not affect engine performance as engine runs on electricity put out by alt. The battery has 2 jobs. Start the car and provide electricity if alt fails.
Is your battery old and actually needs replacing? I ask because a short somewhere in electrical system can cause battery to drain down in a few days. Same with some component still being on when it shouldn't be on.