alright just for some reference, I changed my alternator belt along with all my other belts. I checked the fuses to see if any were blown and none of them were. I took out my alternator and got it tested at a local pep boys here are the readings Battery volts 14.67| ripple volts 0.32| lamp on volts 2.16| lamp off volts 14.49. Now heres my problem. everytime I turn my head lights on my rpms drop and when I push on the accelerator the rpms are rising slower than they would with my headlights off. Also when I turn my heater on it stumbles above 3k(and it is at or above operating temp.) I am very stumped, I searched forums already to no avil. Please someone help me. Thank you for your replys in advanced :-)

 

what is the voltage in the car when this is happening???

 

The voltage is around 13-14 wen its on normal idle with the headlights off and the heater is off. With the headlights and heater on it drops to 12 sometimes even lower

 

if it at anytime is dropping under 12 volts, you have a bad alt.

It needs to be at 13.5 volts to charge the battery and anything under 12.6 volts means the alt is not producing enough power to even run the car.

 

I have a similar problem. I just got the battery and the alternator replace about a month ago. Ran at 13v and than few days ago I just wouldn’t start. It would lose volts fast when in Neutral and die. Had the alternator and battery check and came out good. When I had put it back in my car it started fine, but would start up at 12v and drop to 8v when I turn on the lights, brake, and everything else. Any Ideas?