Alternator swap question

Reply Subscribe

Thread Tools

Search this Thread

Jan 25, 2011 | 11:34 PM

glovemeister

Thread Starter

Cargo Master

Joined: Nov 2010

Posts: 3,244

Likes: 40

Alternator swap question

Why exactly is it that people want whats called a 3g, over the stock alternator? I anticipate better power output. Seeing as how I am putting kc lights, winches, and compressors on my pickup I am going to need this. Now why couldn't I just purchase a 100-200 AMP alternator from like Summit Racing and install it? I assume it is double almost stock output, yet I don't need to fool around with all the conversion business?

Please help me out here.

Jan 26, 2011 | 12:02 AM

LCAM-01XA

Postmaster

Joined: Apr 2008

Posts: 4,802

Likes: 1

The 3G alternator, at least the one that everyone goes after with that swap, is rated at 130 amps from the factory, and some actually crank out more. Yes, you can achieve the same or better power output with an aftermarket alternator, but it's not cheap, and while you do have a warranty you still have to wait for the replacement to come in the mail - with a factory j/y unit you can have one in your truck and two on the shelf in the garage, and still be $100 ahead in the whole game.

Also, FWIW, many aftermarket high-output alternators are actually 3G alternators with different windings and rectifiers - 3G really identifies the type of the alternator, or the design of it if you wish, it is not a brand name or anything...

Jan 26, 2011 | 12:38 AM

glovemeister

Thread Starter

Cargo Master

Joined: Nov 2010

Posts: 3,244

Likes: 40

Ah I get ya! So its largely a cost thing, fantastic.

Jan 26, 2011 | 12:53 AM

LCAM-01XA

Postmaster

Joined: Apr 2008

Posts: 4,802

Likes: 1

Yup, a good-condition junkyard alt can be had for as little as $10 sometimes, and if you get several at once you can mix and match to make a real nice one, or you can just keep the others as spares. Also a factory 3G alt will have a very good power output at idle immediately upon startup, whereas some aftermarket 1-wire alternators require you to revv the engine up high before they turn on.

Jan 26, 2011 | 03:35 AM

cj06

Posting Guru

Joined: Feb 2010

Posts: 2,006

Likes: 2

From: CASA GRANDE AZ

Ford Fuel Injection » 3G Install Tech

Jan 26, 2011 | 10:46 AM

79F-1504x4

Senior User

Joined: Apr 2004

Posts: 141

Likes: 0

From: Muskegon Mi

You could totally pay POwermaster 200 bucks for a good alternator if you want. I pulled my 3g for 20 bucks, and it's 170 amps. I even got the fuse and all the wiring. It took me longer to bolt it up than it did to wire it.

Jan 26, 2011 | 02:22 PM

ArdWrknTrk

pedant

Joined: Jan 2008

Posts: 23,576

Likes: 40

From: EXTREME southwest CT

The main reason for me was the stupid charging plug that kept melting and shorting out both the alternator and the battery.
I was one of the fortunate ones and didn't have a fire.