so i got my new alternator from napa. ok i got it put it in and everything. started the car, 13 volts perfect. but then i rev the engine and the volts go up with the gas. WTF. if i go from 1000rpms it is at 13 volts when i hold it at 2000 rpms it is up in the red about 18. so is my alternator defective? i need to know by tommorrow so i can return it if it is messed up. Thanks

 

by the way it is a 94 amp alternator. is that right for an 86 305?

 

I would say either the gauge is malfunctioning or the voltage regulator is no good in that alternator. Before you take it back, check the voltage across the battery terminals (or from the alternator + terminal to a ground) with a voltmeter,car running, to verify the reading. (borrow or buy one if you have to, youll need it again someday). You want to see about 14 volts, with no more than +-1 volt difference at higher rpm levels... any more or less, take it back.

 

I have a digtial lighting cap for my system. with the alternator before it was always 13.0 The lighting cap shuts off with low and high voltage. low being 11.0 and high being 15.0 so i know the voltage is going over 15 volts because the lighting cap is going off.
so i guess its the voltage regulator then? so it is broken?

 

I have an 86 bird and at autozone they got 108 amps for 60 bucks. not sure what you paid.

 

i just wanted to make sure i wasn't running a high amp alternator and it should be lower. thanx. this one is 94amp for 70$ and 27$ core change till i give the other one back.