steadily dropping voltage.

[southrneclipser]

ok so my 95 eclipse 420a is all stock with factory stereo.

Histroy is: bad rear main seal. so i pulled engine and tranny, fixed it, put it all back in.
I replaced my aternator and battery and at first it was at about 13 volts, but as the car is running, the voltage drops lower and lower until it dies. I took the battery to advanced auto parts and recharged it. So i put it back in and drive to advanced and get the altenator checked. They say everything is good, but the voltage still drops. I'v been over my entire harness and i'v found all tight connections with no cuts or splices. So wy is my battery dying. The belt is tight on the alternator (remanufactored) and the wires are connected good. My power and ground terminals on the battery are new and tight. I have no accesories that would drain the battery. I don't use A/C and i have a stock radio.

I don't know if this matters but when i play the radio the speakers will pop and cut off for a second which it has never done before.

So anyone give me your opinion on wy this is happening.

 

[southrneclipser]

update: I put a voltemeter on the alternator wire where it connects to the fuse. I know it was reading the alternator voltage output and not the battery voltage. The altenator was putting out 6 volts at idle and i revved up and it's max voltage output is 7.5. Is this normal? I know i have the OEM 90 amp alternator but how many volts should it be putting out.

 

[99spyyyyder]

Yeah no doubt my vote goes to a bad alternator. at idle you should charge from 13v at least. if you throttle up to 2k rpm's or more than you should charge anywhere from 14.5v to 15v. If you toss a new alternator on you should be golden. good luck!

 

[RoryBarron]

Yea definitely the alternator. It should put out at a minimum somewhere around 12.5 volts

 

[zhjiln]

... when you turn on your headlights it will drop to 12's, but then should come back up to high 13s quickly ...meaning the alternator is doing its job ...

if not, its just running on your battery and will kill it quickly

 

[brassc2007]

usually when you get a popping sound or humming sound through the radio it is a sign that the voltage regulator is bad that is what i have found out in my experience.

 

[i_nick_2005_i]

ALTERNATOR +2 ^^^ No question. There is nothing else that would cause the problem you are asking, given the "checks" you've done.....

For reference: Our alternators are JUNK! Period.

Hope that helped, if not I'm sorry. But: Thank God for Lifetime Warranty!

 

[southrneclipser]

Update: So now i have to get a new alternator anyways because the new one i put on started humming very loud then it started smoking and then it caught on fire. So i'll be picking up a new one in a few hours.

BTW bassc2007 you said my voltage regulator could be bad. What is this and how do i check it?
Thanks everyone for the help

 

[brassc2007]

i believe on our cars the voltage regulator is internal in the alternator.

 

[deerhunter0881]

^^^^^^ it is

 

[brassc2007]

maybe that is the cause of the fire a fire totaled my car out once but luckily it was just a cavalier

 

[99spyyyyder]

Yeah on these models the voltage regulator is built into the alternator. if the voltage regular fails your alternator will either. A. not regulate the charge, so you'll massively over charge. i've seen up to 18 volts. or B. you'll charge way too low. which is what you're experiencing. slap a new alternator on and you should be in good shape.