battery or alternator?

[aimone 4]

ok so last night and all day today everythings been great. setup has been beatin pretty good. ok so i went to my ol' lady's house today and had no problems what so ever on the way. my car set for 4-5 hours. i go to leave and my car wouldnt start. thought it might be a loose batt terminal checked that didnt work. my voltage meter said 12.8 turn the key and it would go to 0.0 then to 9.0 and back to 12.8. ended up using a jump box to get it started and voltage went right up to like 15.3 with the headlights on. if i turned my volume up over 1/4 up the stereo would shut off ,lights would dim ,and voltage would drop to like 9.0 ...hit the highway and i could turn it bout 1/2 way up before it did that again........

so what do ya'll think? battery or alt?

in about 2 weeks im gettin a new big batt up front and either a h/o alt or a 100amp alt from a suburban and a 2nd batt in the rear.....

i just gotta get by for now till i get my money in 2 weeks

car is a 76 chevy caprice

stock alt and batt

4 ga big 3 . . . .going to 1/0 in 2 weeks also

any help?

[CrazyKenKid 64]

i say battery!! b/c if it was the alt your car wouldn't go from 9 then back up to 12! but more times then not i maybe a combination of both of them.

also check your belt and did you pop open the hood and check the battery out yet for a swell or crack or something out of the ordinary

[aimone 4]

i think it was a combo of both i took a brand new stock alt. off of one of my dads motors in the garage and got a $50 battery and things are fine for now.....thanx though

[Kanaworm$ 292]

Sounds like your battery! As soon as it was under load it would drop the voltage!

[CrazyKenKid 64]

fixed? congrats!!! and good luck with the next setup!