i swear this cars never gonna run right. 1974 caprice with a tpi 400 with the original 74 belt system

2 different brand new 3 wire internal regulated alt neither work
both tested at autozone and there good
new battery
12v at output stud
12v at thicker red wire of 2 wire connector

not charging at 14v it makes just enough voltage to keep the car idling which is about 12.25

EXTREMELY annoyed with this car seeing as im 18 been working on it for a year and a half and still dont have a working first car. the back seat is like a couch i just wanna lay some pipe down in it.

 

oh yeah and i can see the alternator turning on and slowing the belt down when i touch the brown wire to the + and sometimes it happens when i touch it to ground

 

Does the "Gen" light in the dash come on when you turn the key to On with the engine not running?

If not, replace the bulb.

If the bulb goes bad the alt will never "know" that the key is even on, and won't do anything.

 

When the key is in the on posistion and when the problem started it used to be dim with the car idling and turn off with the rpm rising now its just off when the motors on and on with the key in on

 

Thats my car same color 4dr vinyl

 

What type of alternator do you have? I would guess a 10 / 12 SI?

 

One is a autozone duralast 10si other is a ebay 100 amp 10si

 

Try troubleshooting what you have with this link...

http://www.oldengine.org/unfaq/10si.htm

CG

 

I got the 2 terminal going to the battery post the battery post straight to + and the 1 terminal (indicator light) going to the indicator light. I know for a fact that this is not a wiring problem.

I read somewhere that autozone tests alternators without load on the so a alternator operating at 50% would come up good i hope this is true i feel like this problem is too simple

I figure ill buy a brand new alternator and return the duralast 1 and see what happens

 

Well don't say you know anything is 100% until it is working (Bad Karma) )

When the key is ON, make sure you have 12V at terminal 1 of the alternator harness / wire. Also, make sure the idiot light / bulb in the dash is the RIGHT bulb, not just "a" bulb.

CG

 

Yeah 12 v and yeah ther the right bulbs