When my car idles my voltage is like at redline, bottom redline. I need more voltage. My alternator is pretty good, it keeps the car running without the battery connected. What would I need to change this besides a better alternator.

 

My car does that too, and I have a 160amp alternator, so I don't know.

 

it may actually be the guage. get a voltmeter and check it or ...cough cough... go have it checked at autozone. The 10 year old guages in your car can not always be trusted

 

Might be the voltage regulator..... With the car running, voltage should read around 13.8~14.2... Its an internal regulator, not easy to replace, from what I hear...

 

And, my alternator does a **** poor job if charging my battery

 

If you've run the engine with the battery unhooked the alternator might be toast. The high power alts. don't last long with a low/no resistance load. Also, do you have underdrive pulleys? They will cause this especially with the fans running.

 

good points

 

If its really low then you have a major problem. My car would only show about 12 volts and it ended up being the fuel pump. As they age they eat up more juice. I bought the a new Racetronix pump and alternator harness and all is good. Adding the harness to my car with the old fuel pump bumped my voltage up to 13.5.