When my car begins to redline and about 5-7,000 rpm my dashboard beings to make a buzzing noise. It will not stop making that noise until either I turn the car off, or while my car is shifted into reverse. My door ajar and parking brake warning lights will illuminate as well.

Also, I replaced my alternator because my voltage kept dropping gradually from the standard reading of 12 to eventually slowly dropping to about 6-7 volts when the car begins to run rough and it dies. But what I can do is redline the engine like above, and it goes right back to 12 volts and everything will work as it should except for my dash will buzz and the warning lights will not go off

Ever heard of this prolbem?

 

#1: Why the crap are you running your motor up to 7k RPM's? Unless you have a highly modified motor, there is no need to run it past ~5500 RPM because peak hp is ~5200 RPM. And on the L28E n/a motor, it's pretty pointless to run it past 5k at all.

#2: So are you saying that even after you replaced the alternator, the voltage will still drop? The dash lights illuminating is a common sign of a dead alternator. Take your car to a local auto parts store and have them load test the alternator & battery. Also, the stock n/a alternator is rated for ~50amps and is worthless to replace with another stock one. Replace w/ a Maxima one or GM 1-wire.

 

I don't race my engine on purpose, it happened when i thought i had the car in gear when i first experienced the buzz

i have a duralast alternator inside it but the same battery

 

also after installed the new alternator i had the old one tested and the machine said it was a good one

 

....

 

yes the volts still drop
unless i rev the engine, then i have to deal with that dam buzzing