Managed to get through the whole thread.

Wondering why not get a new unit from alternatorman with the 140 amp upgrade?

Fits in the stock location, uses all the factory bolts, should last as long as an oem new unit, and has the 140amps to eliminate any dimming issues.

Thanks
Tony

 

I installed the alternator today, physically larger than the stock one but a little easier to get in. Christmas stuff to attend to, so I have yet to fire it up. Just excited that it looks to be the answer!

 

So the 20989650 seems to be the replacement for the old 15263859?

I did a 145 remay swap back in 2012 or 2011. Now my buddy's Z28 needs to swap his. Since I told him to upgrade while it has died.

Merry Christmas

 

I have a 200a alterstart in mine and it works great!

 

Why when the stock one is 145 and probably cheaper? I've installed several $50 ones with zero issues, and if you don't like used get a rebuilt or new one.

 

If you get a connector with 4 wires just cut the 3 that aren't used. They do nothing.

Glad to see you guys doing well with this, for those of you that have so many questions, all the answers are in the FIRST post of this entire thread.

Only thing that hasn't been addressed I believe is whether to put the alt in with the bracket attached. NO! The bracket needs to be separate. Slide the alternator between the sway bar and fans. It'll go, just push. Don't loosen fans or anything.

 

Read the first post in this thread. Durability is the problem.

 

ttt

I'm bumping this thread as it's relevant to my situation. I was driving to Augusta GA yesterday to see my girlfriend (I live in Columbia SC) and about the time I got to the GA border I had a "Check Gauges" light come on. I looked and the voltage gauge was very low and just kept getting lower. I was just cruising down the interstate in 6th when it happened so it was the result of some WOT pull or anything. After a couple of minutes all my gauges other than the "Oil Pressure" gauge died, (tach, speedometer, odometer, etc) the headlights when out, but some of the lights like the seat belt, check engine, and ABS lights would flicker on and off and make a beeping noise. Oddly enough the radio still worked as did the power locks and windows even though they were week. I was able to limp it the rest of the way to my girlfriends house but that was a PITA as the motor would surge up and down at idle and while it would rev fine in neutral or with the clutch compress it would choking if you tried to rev it much with a load on the wheels.

Here's a video right after I got to my girlfriend house before I turned it off.

I have to get it back to SC to really look at it, but I'm guessing it's likely the altenator went bad. Car barely has 34K on it and in terms of the motor is stock other than a Flowmaster exhaust and drop in K&N. I did put a Kenwood DVD player in it about 2 weeks ago with one of those Metro modules that lets you use the steering wheel controls with it so I have both of those grounds running the the factory harnesses ground as well as the ground for the parking brake to let it play DVD's so maybe I'm over-grounding the factory ground which killed my alt? The only other stereo mod is some CDT convertible component to replace blown door speakers.

Anyway to make this relevant to this thread I'm wanting to upgrade to the 145 volt truck alt. I want to make sure I buy the right parts for the job though.

Is this the correct alt to buy? All the review are people with late 90's and early 2000's GM trucks upgrading. It's supposed to be a AD244 housing. People upgrading to it are claiming to have to run a slightly longer belt with it though as it's a larger housing which changes the pulley location. Is this necessary on a Fbody? Do we need to do a larger power and ground cable upgrade for this alt? I think it's refurred to as a "Big 3" mod?


Also just to make sure this is the harness that we should replace correct?
http://www.ebay.com/itm/LS1-Alternator-Wiring-Connector-Pigtail-98-02-Camaro-Firebird-1-wire-/271528818582?hash=item3f3860f796
Thanks for your help,

Jesse

EDIT: BTW after I cut my car off it was dead and the switch would click, but not try to turn the motor over. After about 30/45 minute it did build up some charge where it would start to turn the motor over but not enough to start it.

 

you can reuse the factory belt.

you dont need to upgrade the wiring (although it would help)

Truck Alt mounts with 2 bolts (rear bracket for F-Body alt is not used)

you can either use a 4 pin 244 or 2 pin 244.. (2 pin 244 would use a new plug)




I have the 2 pin AD244 out of an 06 Silverado on mine and its been fine for almost a year since I put it in

 

Thanks. I'm actually looking at belts right now. Looking for a Gatorback but it looks like GY Gatorback belts are now Continental branded and called Continental Elite.


http://www.amazon.com/gp/aw/d/B000C3...ZpL&ref=plSrch


BTW I was referring to the alternator as using volts instead of amps. Sorry for the mistake. Lol

 

I used the factory size belt on mine when I upgraded to a '04 4 pin AD244. I did swap the pulley from my stock alt to the "new" alt. I use Dayco belts. I also didn't upgrade the wiring because I was just looking for more idle volts/amps to get rid of my dimming lights and whatnot from my choppy cam. Worked great.

 

All that you have to do to do this is get a truck alternator and bolt it in, the only thing that absolutely has to change is you have to pull the bracket that bolts to the back of the f body alternator, there is no place for that bolt to go on the truck alternator.

 

Let me ask y'all this. Why do some people swap their factory Fbody pulley over to the truck alt? Does it affect where the belt is located front to back in relationship to the other pulleys? If they're different diameters that could affect the alternators reliability depending on the crank pulley diameters between the two different vehicles? I'm guessing that most LS based motors come with the same crank pulley diameter? The reason I mention this is because I also own a Lightning and a Terminator and if you add a bigger lower pulley to up your boost you are supposed to swap out the alternator pulley to a larger diameter one depending on the size crank pulley you're run to bring the speed the alternator spins at back to factory levels or you'll overspin it and likely burn it up. A different diameter alternator pulley will change the speed it spins at.

 

When I compared F body alternator pulleys to truck pulleys they were the same diameter. I also compared 95 amp truck alternator pulleys to 145 amp alternator pulleys and they were the same. The 145 amp alternator has a larger case and therefore moves the pulley out a hair more so it makes it to where you have to pull a little further on the tensioner to get the belt on but it still goes on and works fine. I've done it on a few f body cars. When I changed my 95 amp truck alternator to a 145 amp I went ahead and put the belt on that it calls for when using the 145.

And on any car you change the crank pulley size you would need to change the alternator pulley to compensate for the change if you wanted the alternator to spin at the same speed it previously did.

 

I changed mine because the truck alternator pulley looked like poop and my LS1 pulley did not. I never compared the sizes. It was an aesthetic decision. I just posted that information in case it was relevant.

 

I work the counter at a parts store and reference this thread when I see people come in with an fbody and charging system problems. One customer from out of town had been through 9 fbody alternators before I told him about the truck upgrade and it solved all of his oroblems.

The fbody alternator isn't even a store stocked item anymore. It was posted that they are rebuilding these with the wrong size components which explains why they can fail nearly right out of the box

Cheers and thanks for the advice, I'm about to replace my own alternator. After 18 years she is bouncing around on the volt meter between 13.5 and 14.2 wildly sweeping across the dial, still passing the test but it's just a matter of time.

 

so is the upgraded alternator off a DURAMAX?

the 20989650

 

I don't know what comes on the duramax, but the right one for sure comes on V8 gasoline trucks. All the necessary directions to identify the right alternator are in the first post. Just go and ask for an alternator for a 03 silverado with a v8 and ask for the 145 amp.

If you want to know if they are the same get the part number on autozone's website for the duramax and for the above listed truck and compare them.

 

I came up with this after going through 10 myself, one literally lasted 5 minutes.

 

cool, thanks.

i went to autozone and got an alternator for an 02 2500HD 6.0 145amp

i got the "Duralast GOLD" that is brand new since it was only $20 more than a reman so i figured why not.