I've replaced the alternator 5 times and know that the alternator is a good one. the battery is good. the fuses/wires/fuse-able links are good. Computer code reads nothing wrong. But the car is running entirely off the battery despite having a good connection to the alternator, and this alternator is a *good* one. What is going on here?

 

Not to be a wise a** but how do you know the alternator is good. Did you have it bench tested? If it is new did you buy all 5 from the same store? You might have gotten a few from a bad run of alts that slipped through QC. What I would do is have the battery bench tested at your local parts store, and buy another alt from a different auto parts store.
Now once youve tested these things check your belt, is it worn? Does it have enough tension? I'm thinking since you replaced the alt 5 times maybe you arent tightening the belt enough. Actually now that I think of it start with the belt first. BE CAREFUL over tightening the belt will lead to failure of the belt, alt, water pump, and even the ac compressor. You should have about 1/4 inch slack in the belt when pressed down on the longest space between components.

 

A) Replaced the belt already.

B) Had an actual mechanic do the work.

C) Had all the alternators bench-tested and No they weren't all from the same store.

D) We had a few bad ones and even the bench-test said they were good, so that's not reliable. What was reliable was the voltmeter the mechanic had and how much the alternator was putting out with the car off.

So with all that in mind, what is the problem?

 

Dusky and I have been trying to resolve this problem via PM once I get the chance I'll post them here so the info can be used by all.

 

Here is the talk dusky and I were having.

dusky:
Alternator was bench-tested. Tested good. It's not the same alternator- we got this one (me and my dad) from carquest. The last four we got were faulty despite testing positive in the bench-test (I mean, one of them had a fan that was catching and their machine didn't pick it up)

The belt has been replaced already and it's not too tight or too loose. My dad's a mechanic (I'm a girl btw) so I was just putting in what he's done and he's stumped. He used a voltmeter to check the alternator and it's putting out enough voltage but somehow it's not getting to the battery and the grounds all have fire and so do the wires/fuses/fusable links.

He thinks the computer might be bad in the car but I don't know how to tell if that's the case and those are really expensive so I'm hoping someone on here will know wtf is going on so I don't have to spend 200 on a new computer.

My dad can't do electrical stuff b/c he's not and never has been good with that.

So if it's not the alternator, the belt, the wires, the fuses, the fusable links, or the grounds, what could it be other than the computer?

rare:
I was giving some thought to your problem today, I realized you might have a pinched wire, it may seem fine by looking at it but if the jacket is dented or crushed you might have broken strands inside.
Refresh me, you said the alt is fine as well as the battery, whith the car running what is the voltage at the battery? As Im typing this I'm reading my trusty repair book, have you checked the voltage regulator?

dusky:
And my car requires the alternator with an in-built regulator so not the issue.

rare:
Have you checked for a pinched wire??

dusky:
IF a wire is pinched, would a continuity tester still show it as having fire all the way through?

If the wire is pinched you should have less voltage and continuity. The continuity doesn't test less/more it just shows if there is fire all the way up and down the line. Voltage on alt/battery is normal.