Carcrazygts2

Only 97/98's actually had 3g's. The newer 99+ trucks ended up getting a revamped smaller case. Those actually only make around 80 @ idle and 130-145 @ 1800. Honestly the upgrade harness isnt required if you have good connections. The factory 2/4 ga can handle 200amps.

OhioLariat

Below is a pic of the current alternator in my '03. I was under the impression that this "2-hole" design designates the "large-case" 130A 3G alt....



... and that the "small-case" 95-Amp 3G alt has four holes like this one.



(Both my '99 and the '03 have the "two-hole" design.)

Am I mistaken that mine is the 130A 3G?

FWIW, the 4G and 6G alternators look altogether different.

THIS ARTICLE seems to give a pretty good rundown on the different designs, though it's Mustang-based.

Andy

Neophyte

500 watts isnt nearly enough to justify a higher than factory amperage alternator. usually factory alternators are 70% or so and you have an extra 30% and that is with everything running. It is important to remember when talking about stereos that they are not pulling full power constantly. Unless you are burping your subs you will very rarely hit even your rms rating. If anything a small secondary battery would be more cost effective and all you would need if you needed anything. Something along the lines of a shuriken 20 series.

If you are gonna go aftermarket alternator and want one that does rated or better you cant do much better than singer alts.

I was running 10k watts at half an ohm in a honda accord with only one extra battery (120 aH) and a 350 amp alt with almost no voltage drop on a 10 second burp.

OhioLariat

Agree. That's why I decided to look into having this one rebuilt.

Andy

white89gt

I use a place here for parts and rebuild them myself. I've got a 130 amp sitting here that charges fine - but it's got a bad bearing in it. Most of the time doing brushes, bearings, and the regulator is all you gotta do.

jethat

I like getting parts like that at autozone. I get the lifetime and that way if it fails all I need to do is give my phone number and I get a new one. Could find better cheaper but then I wouldn't have that warranty simplicity..

OhioLariat

What's involved with changing the bearings? Do you need a press? (Heck, I might be able to make one good one out of the two I have.)

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white89gt

No press needed. It's pretty straight forward. The nice thing about the 3G is that the diodes are really good, and usually only go bad if you get a direct short. I found this video that shows you what is involved. I visited their webpage and their kit is 30 dollars. They have an upgrade kit that puts you up in the 170-180 range for about 85 dollars (IIRC).

white89gt

Forgot this link... my bad.

http://alternatorstarterrebuildkits.com/product/3g/

EDIT:

I just found this on Amazon. I'm going to give try one out on the alternator I've got.

white89gt

One more thing I do is clean them up and paint them with Alumiblast. I'm not sure who sells it, but I get it from my Buddy that builds transmissions. Makes it all look brandy new. Pretty sure he buys it from Transtar. I can find out if you're interested.