Upgraded Service Life: Pressure-Fit High-Capacity Diodes for improved heat dissipation
Improved Reliability: Double insulated rotors and stators to reduce signal degradation
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How to Replace Alternator 2003-04 GMC Envoy XL
Created on:
Tools used
Hammer
Flat Blade Screwdriver
15mm Socket
T30 Driver
8mm Socket
10mm Socket
Ratchet
1. Disconnecting the Battery
Disconnect the negative battery cable with an 8mm wrench
2. Removing the Air Intake Hose
Loosen the two air intake hose clamps with a flat blade screwdriver
Remove the T30 Torx bolt from the air intake hose
Pull the intake hose up and off
3. Removing the Serpentine Belt
Familiarize yourself with the belt routing diagram
Attach a 15mm socket and ratchet to the tensioner
Push the tensioner down to loosen the belt
Pull the belt off the center pulley
Carefully release the tensioner
Pull the belt off the alternator
4. Removing the Alternator
Disconnect the alternator wiring harness
Pull back the alternator wiring lead boot
Remove the 19mm nut from the alternator lead
Pull off the alternator lead
Remove the two 15mm bolts from the alternator
Pry the alternator out with a flat blade screwdriver
5. Installing the New Alternator
Hammer out the alternator bolt rings
Lower the new alternator into place
Insert the two 15mm bolts into the alternator
Connect the alternator wiring harness
Put the alternator wiring lead on its stud
Fasten the 10mm nut onto the wiring lead
Put the wiring lead boot into place
6. Reinstalling the Serpentine Belt
Pull the belt over the alternator pulley
Make sure the belt is routed correctly, using the belt diagram
Attach a 15mm socket and ratchet to the tensioner
Push the tensioner down to loosen the belt
Pull the belt onto the center pulley
Carefully release the tensioner
7. Reinstalling the Intake Hose
Put the intake hose into place
Tighten the two intake hose clamps with a flat blade screwdriver
Tighten the T30 bolt into the intake hose
8. Reconnecting the Battery
Reconnect the negative battery cable with an 8mm wrench
Brought to you by 1AAuto.com, your source for quality replacement parts and the best service on the Internet.
Hi, I'm Don from 1A Auto. I hope this how-to video helps you out, and next time you need parts for your vehicle, think of 1AAuto.com. Thanks.
In this video, we're going to show you how to replace the alternator on this 2003 GMC Envoy XL with the 5.3 liter V8 engine. The items you'll need for this are a new alternator from 1AAuto.com; 8mm, 10mm, and 15mm socket and ratchet; T30 Torx bit; flat blade screwdriver; and a hammer.
Use an 8mm wrench to disconnect the negative battery cable.
Start off by loosening this hose clamp and this hose clamp, and then, removing this T30 bolt up here, and we'll just fast forward as Mike does that. Now, pull this hose free and then lift that air intake hose up and out.
Next, you want to locate your serpentine belt diagram, which is located right here on the shroud, and you just want to refer to this as you're trying to put the belt back in place and make sure that you have one of these before messing with the belt. Then, using a 15mm socket and ratchet or a 15mm wrench and another wrench for extra leverage, just push down on the tensioner and then pull the belt up and over that center pulley and carefully relieve the tension on the tensioner. Pull the belt off your alternator and then lift up on the tab on this harness and disconnect it.
Pull back this boot and then remove this 10mm nut. Now, remove these two 15mm bolts, and we'll just fast forward as Mike does that. Now, using a large flat blade screwdriver or pry bar, just pull the alternator up and out, and you'll most likely have to pry both sides out.
Using a hammer, just hammer out the rings here, to make it easier to get new the alternator down in place. Make sure the harnesses are out of the way and lower your new alternator down. Line it up and push the 15mm bolts through. We'll fast forward as Mike tightens those up. You do want to make sure that you get that nice and tight. Reconnect the harness. Put this wire back onto the stud and replace that 10mm nut and tighten it up, and slide that boot back up into place.
Put your belt back up over the alternator pulley, and while you're doing that, make sure the belt is on each of the pulleys correctly and that hasn't fallen off any of them. Then, just double check with your belt diagram that the belts in the right order and on each of the pulleys. Put your wrench or socket and ratchet onto the tensioner and pull back on the tensioner, and just push your belt underneath that center pulley. Then, carefully release the tension and make sure your belt is on all the pulleys correctly.
Now, feed your air intake hose back down into place and make sure to push down all the way, and then push this end back into place and then tighten up those two hose clamps, and I'll tighten up the T30 bolt. Then, reconnect your negative battery cable.
We hope this video helps you out. Brought to you by www.1AAuto.com, your source for quality replacement parts and the best service on the Internet. Please feel free to call us toll-free, 888-844-3393. We're the company that's here for you on the Internet and in person.
ALA94411
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Product Reviews
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4.42/ 5.012
12 reviews
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James
February 3, 2022
Ended up being the wrong part. 1A stood behind it. Sent me a shipping label for the return. Sent the part in. Reimbursement came quickly. I've used 1A many times previously and will continue to use them with customer service such as this.
Chevy 8.1L alternator
Mark
March 13, 2022
Worked as it should, shipped fast
Very well please
DONALD
March 16, 2022
easy to put in and it looks exactly like the one I took out I love it and very fast shipping appreciate that
Yes...TRQ makes a VERY high quality alternator at a great price...with a lifetime warranty. Buy it!
Lyle
July 7, 2022
I purchased this for replacement of my oem original alternator in my Tahoe. They both share the same amp rating, and the original still tests in limits. The TRQ alternator keeps up with the loads better than oem. It's got a slightly noticeable noise, but it's an improved airflow design to keep it cooled better with larger air foils. I don't mind that increasing my reliability!
They need to talk to their supplier
Richard
January 10, 2023
The first one made a whining noise they sent me a new one and it whines just as bad I give up
Perfect
KEN
January 29, 2023
Great reliable quality
High Quality OEM parts at a very competitive price
N
March 15, 2023
For the quality, the price and the fast shipping you can't be the parts and service at 1A Auto. They are competitive with most local automotive parts suppliers and in many cases even cheaper with free shipping. You just can't go wrong buying parts from 1A Auto
Perfect
Koester
December 7, 2023
Exact fit, looks OEM. Got it fast and works great
1A auto could charge more for the products because of the videos!
Steve
January 10, 2024
It was so easy to put on. I watched the video and had not surprises. The serpentine belt slipped off, but that was the only hiccup.
Stephen
February 6, 2024
Fit like oem model, easy installation
Not sure whether saving a few bucks was a good idea.
Richard
February 25, 2025
It still makes a whining sound, even after they sent me a replacement.
Customer Q&A
whats does diy mean fromthis alternator to above alternator ?January 21, 2022
Ernest S
10
DIY Solutions is a brand we offer. This listing is for a TRQ branded alternator.
January 21, 2022
Andra M
Is this new?February 10, 2022
John D
10
Yes this is a brand new alternator!
February 10, 2022
T I
Will this fit a 4.3 envoy xl?February 11, 2022
Timothy T
10
This part will not fit your vehicle, but we may have a part that is listed to fit.
Please enter your vehicle's year make and model in the search bar at the top of the page. This will display parts guaranteed to fit your vehicle. Just be sure to verify all of the information shown in the Vehicle Fit tab before ordering.
February 12, 2022
Cristina P
Amps?March 21, 2022
James H
10
It is 145 amps
March 21, 2022
Cristina P
Will this fit a 2004 GMC Sierra 1500 5.3?April 28, 2022
G O
10
Yes, this part will fit your vehicle.
April 28, 2022
Emma F
Will this fit an 07 Chevy avalanche?May 10, 2022
Kevin C
10
This part will not fit your vehicle, but we may have a part that is listed to fit.
Please enter your vehicle's year make and model in the search bar at the top of the page. This will display parts guaranteed to fit your vehicle. Just be sure to verify all of the information shown in the Vehicle Fit tab before ordering.
May 11, 2022
T I
Need alternator for 2005 GMC Yukon with 5.3 engine. Is this the correct item?May 29, 2022
John D
10
Currently, we do not carry this part for your vehicle. We're always updating our inventory so please check back soon!
May 31, 2022
Jessica D
Is this good for a 2006 Chevrolet trailblazer LS v6?June 27, 2022
Andrew E
10
This alternator is specific to 2006 Chevrolet Trailblazer models with a V8 5.3L and (8th Vin Digit M).
June 27, 2022
Jessica D
will it fit 2003 duramax?August 18, 2022
John D
10
Please enter your vehicle's year make and model in the search bar at the top of the page. This will display parts guaranteed to fit your vehicle. Just be sure to verify all of the information shown in the Vehicle Fit tab before ordering.
August 19, 2022
Emma F
Will this fit in a 2004 gmc yukon slt ?August 27, 2022
B R
10
Hello, could you provide your VIN#, to confirm fitment, please?
August 27, 2022
Ricale A
Will this fit 2004 chevy tahoe?October 3, 2022
Terry W
10
This is listed to fit
2003-2004 Chevrolet Tahoe V8 5.3L (8th Vin Digit T or Z)
2003-2004 Chevrolet Tahoe V8 4.8L (8th Vin Digit V)
October 3, 2022
Kelly S
How do I know if I need a 145amp or 105amp alternator for a 2004 Chevy Silverado 1500 5.3L ?December 1, 2023
Barry V
10
Mine was a 2500 duramax diesel with two batteries so required 145 amp. Plugging in your make and model the1A auto software should verify your choice and correct an wrong choice
December 1, 2023
Garry P
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