S-10 Forum banner

How To: High Output AD244 Alternator for ~$80

348K views 711 replies 145 participants last post by  Scottie0308  
#1 ·
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.

--------------

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 :p *

--------------

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.

--------------

Here are some pictures of my AD244 in action:

Output at idle with just my headlights on:

Image



Output at IDLE with my system cranked to the max:

Image



Output at IDLE with all accessories on (all 4 headlights [quad beam mod], a/c on MAX with fans at #3, fog lights, and my system cranked to the max:


Image




13.96 can be lower than most would like to be.... but a stock CS130D would be gasping for air if I was treating it like that.

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.
 
#174 ·
Hmmmm Im gonna hafto do this. My lights dim when I turn on my 2 set of bumper lights....then when the fans kick on, well you know. Ill go junkyard searching this week. I have both a 2.2 and 4.3. When I get one, Ill see if it fits my 2.2 as well.
 
#175 ·
I need to upgrade my big 3 and do this too. Running underdrive pulleys and an efan taxes my electrical bigtime.
 
#177 ·
I read most of the thread and I see a lot of people are concerned/worried about belt sizes. Method I have seen used which seems to work great is take a piece of string wrap it around all your pulleys as if it was a belt.

Cut that string at the exact length go to your local parts store and find a belt that matches up. Just an idea.

I'm going to pick up a new AD244 next week hopefully and go from there. Great info on here thanks guys.
 
#179 ·
mine

Image


Image


Image



bought it USED off ebay for $50 and $16 shipping, still looks brand-new
also upgraded the charging wire to some 1/0. Still have 2 runs of 1/0 for the system.

Also i did not buy a new belt because i had a spare alternator for my other car that had a much smaller pulley on it, just switched pulley between the 2. and another plus is now its spinning faster too. ;)
 
#185 ·
If the sierra had the 4.3L in it, then yeah it did have the same alternator.

There isn't a specific "AD244" stamped right on the case. Look at the pictures I just posted of my AD244, the "sidewall" between the pulley and the top of the alternator is a lot bigger than the one you bought.
 
#191 ·
Sometimes the obvious is so hard for us to see...
hey guys, i am looking at an alternator on ebay thats going for like $20. it's for a 99 sierra. the guy has no idea of the part number as it is in inventory. the ad says it should fit the following:


1999 Sierra 1500 & 2500 4.3L
1999 Silverado 1500 & 2500 4.3L
Then you posted....
i have no clue. it was off a 99. i didn't know they came with a 4.3. hmmm....
It's that fine print that gets ya...lol. Well you still got a good deal on a spare alternator.
 
#195 ·
So I bought an alternator off of eBay that did not have the model # listed but it was listed a 145a, has the 4 prong plug and was said to be off of the list of vehicles for the ad244. So I figured i would give it a shot and ordered it. Its turned out to be a DR44. The bolts appear to be spaced the same and the plugs match, will this alternator work?
 
#202 ·
Ohh!! I've seen that alt before!

*sigh*

Ok..... here is my background with that alternator. airnathan over at Zr2USA bought one of these from cknaffle through a group purchase. He was told that the alternator had low mileage (which it did in fact have low mileage) but he couldn't get the thing to work how he wanted it to. I remember this because I was like "are you sure it's a genuine AC Delco AD244?" and he was like "well no, it has DR44 stamped right on the case" and I was baffled by this because it was a 145A alternator.... it just wasn't an AD244 (it very well could be an AD244, but it wasn't the same AD244 that I've known to love).

Now..... that alternator may very well work for your application. But please do have caution that it MIGHT not work (meaning you won't get the output that you want out of it). The only reason I say this is because airnathan over on Zr2USA had this same problem and we couldn't figure out why it was acting up on him (bad output).

So, take the install with a grain of salt knowing that you could potentially have problems. I'm not saying that it won't work, just saying that there is definitely a possibility that it isn't what you're looking for.

Sorry man :(
 
#203 · (Edited)
Thats what I was afraid of. I was just doing some google searchs about it and ran across this


"The two systems are not cross-compatible. Both systems receive a modulated signal back from the regulator, but that does not mean that the signal is the same.

The PCM provides a PWM signal on the regulator input, and reads the field duty cycle as well as system voltage to adjust charging with the DR44G alternator.

Your older AD244 is managed in a similar fashion, but the old regulator still has the capability to run without feedback - that is why you could make it start with a jumper to B+ ( I strongly recomend a current limiting resistor in that jumper circuit!)"


I assume dr44g is the same is the dr44 that I got. I don't completely understand what this guy is saying, but the just of it seems to be that it wont work. lol. That sucks.
 
#204 ·
Yeah that makes sense. I was guessing that for some reason the DD44 alternator wouldn't be compatable with our PCM's, while the AD244 would bolt right up.

Do you happen to know what vehicle the DD44 alternator that you bought came off of?

I'll be on later this afternoon after class.
 
#205 ·
Oh and if the alternator does in fact NOT work for you, I'll be sure to have it included in the OP to clarify that you shouldn't buy the DD44 alternator.

Sorry if that sounded harsh lol, but I only call it a mistake if you don't learn from it ;)

If you could give us some voltage readings, amperage readings would be great too, of the DD44 alternator installed on your truck, that would just be awesome. Use a DMM, not the volt meter on your gague.

Thanks man :tup: