Rep Power: 0

Hey. I've been searching the forums for about a month now trying to figure out what my numbers mean but haven't found out a real answer. My alternator died for the second time last month. A few months after i put that alt in the batt light would flicker around 2500 rpms but i never got it checked. One night when leaving work i noticed a big dimming of my headlights when i accelerated on the highway. Next morning the batt light came on and i needed a new alt again. New alt doesn't show any problems yet but i got a volt meter and check it daily b/c im paranoid. Is it normal for the voltage to be around 15v when its a real cold start (like 20F)? Also I know we have an ELD in our cars and just wanted to know if its normal for voltage to drop when at idle after driving on a highway for like 30 mins to like mid to low 12s (either with lights and heat on or off)? Im just wondering if the ELD would really cut the output of the alt that much. Thanks.

 
Rep Power: 256

thats normal. the car is supposed to run at 14.7volts while charging with no acc on. my car ran 12.4 with sub pounding, headlights on, and everything at full load.

 
Rep Power: 813

yes normal. cold days starting can get upto 15.5v before the car warms up. otherwise during driving it fluctuates anywhere between 12.2 and 14.2v.

 
Rep Power: 0

Thanks. I just wanted to make sure. i think the old alt was prolly defective since the batt light would flicker so much. I doubt my 500w sub killed it.

 
Rep Power: 256

yeah 500 watts is nothing. i was pushing 3000w on my stock alt very carefully and it didnt kill it.