4.3L GM Motor Alternator Upgrade - The cheap way

[BeachJoshua]

Copied from S10forum.com

Here is a little write up/explanation on how to swap your stock CS130D alternator for an AD244 alternator off of most of the full size trucks.

For those of you that NEED a bigger alternator, weather it be because of off-road accessories (winches, lights, etc) or because you need the extra amperage due to a bigger sound system, you would probably upgrade to an aftermarket alternator to meet your needs. Well, unless you are paying $300+ for a built alternator with a good stator and regulator put in, you will loose voltage at idle when you purchase the upgraded one. This is where most people have their concern, especially you off-road guys.

For example, when you put a 160 amp stator in a stock CS130D (4.3L) case, you will get the 160 amps, but only at about 1000 engine RPM's. Our 4.3L's idle at ~550-600, so the output is a lot less, voltage and amperage. I've found that my "built" CS130D only put out 45 amps and 12.8v at idle, when I needed a LOT more than that to keep my lights from dimming at idle.

So, our goal here is to get output (amperage and voltage) at idle as well as our required output at speeds greater than idle. With the AD244, you can have the best of both worlds.

*You can pick up a used AD244 alternator from your local junkyard for ~$40-$50, depending on mileage/condition*

The AD244 alternator came off of several full size pickups, from different years. There were two versions of the alternator made, a 130A version and a 145A version. You can call your local junkyard/salvage yard and ask them what it came off of, how many miles are on it, and what version it is (130A or 145A). Here is a link to everything you need to know (including what vehicles it came off of) about the AD244 (thank juddspaintballs for the link)

http://www.wai-wetherill.com/products/partimage.cfm?wai_num=1-2419-21DR

*The AD244 alternator will bolt right up to the stock alternator bracket on the 4.3L with NO modifications to the bracket. The only thing that is different is that you won't be using the 3rd bolt that is on the backside of the alternator. The CS130D has this, but the AD244 doesn't. You won't have any troubles with the bolt not being there.*

*The AD244 uses the same wire harness as the CS130D. It is a plug-and-play application.*

Now, I know what you guys are thinking..... "well dude, I need wayy more than 145 amps." That's what I was thinking too when I was doing this mod. I've got a decent sized sound system in the truck and some aftermarket fog lights on my safari bar, so I needed the extra amperage.

Bench tests have proven this alternator to put out 200+ amps at idle when cold. Yes, that's right, at idle.

When the alternator is warm it will easily put out 100 amps at idle,which is way better than the CS130D which is only capable of producing ~40 amps at idle.

It is a slightly underrated alternator (you audio guru's out there know what the term 'underrated' means and how it compares to the quality of a product). I can crank my system to the max and have no voltage issues with it when I'm at idle. I'll maintain a 14v and my lights don't dim.

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Now that you have the alternator, you'll be needing a longer belt. I can't say how long of a belt you'll be needing, but the stock one won't work. If you DO get the stock belt to work (some have) I STRONGLY don't recommend it. It will put a bigger strain on the bearings in the alternator and can cause premature failure. It's worth the extra $35 for a new belt.

*You will need a belt that is 1"-1.5" longer than stock. For some reason, the lengths of belts changed from year to year (even 98+) so you'll have to do a little bit of math and figure it out on your own *

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I also highly recommend doing the "Big 3" upgrade when doing the AD244 mod. Stock wiring CAN take the 200+amps that the AD244 puts out, but if you are having problems with it, then it is probably the wiring.

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So, if I had things my way, every s10/blazer would have an AD244 as their alternator, even if they have a stock electrical system.

[white4d96]

Hm, good idea. Wonder if this would work on 3.1 cars (we use the CS130d as well, the shitty things.) What trucks did the AD244 come on?

[white4d96]

Bump, tried the link showing applications on your post but it didn't work for me. Anyone know what trucks these alts came on?

[z71kris]

These mostly came on Tahoes/Yukons and newer 03+(I think) GM 1500-2500 trucks.

[white4d96]

Oh okay. That kinda sucks because I'm not sure of any salvage yards around here that deal in late model stuff...Guess I'll just keep looking around. Thanks for the info.