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How to Replace Tail Light Combination Junction Block 1999-2004 GMC Sierra 2500
How to Replace Tail Light Combination Junction Block 2002-06 Chevy Suburban 1500
Created on:
Tools used
13mm Socket
Flat Blade Screwdriver
Rust Penetrant
Ratchet
1. Removing the Taillight Harness Junction
Disconnect all of the harnesses from the junction block.
Remove the 13mm bolt that secures the block to the frame.
Pull the bracket free.
Pry out the tab on the back of the bracket and slide the junction out of the bracket.
2. Replacing the Taillight Harness Junction
Slide the junction into the bracket.
Feed the bracket back up into place.
Replace the 13mm bolt.
Reconnect the harnesses
Brought to you by 1AAuto.com, your source for quality replacement parts and the best service on the internet.
Hi, I'm Mike Green. I am one of the owners of 1A Auto. I want to help you save time and money repairing and maintaining your vehicle. I am going to use my 20+ years' experience, restoring and repairing cars and trucks like this, to show you the correct way to install parts from 1AAuto.com. The right parts, installed correctly - that's going to save you time and money. Thank you and enjoy the video.
In this video, I am going to show you how to replace tail light harness junction on this 2002 GMC Sierra. The only tools you'll need are a 13mm wrench, screwdrivers, and some penetrating oil. This is the same for a lot of different GM trucks.
Okay, if you are having some problems with your rear lights. The another place that can go bad is this junction block. This is the back frame, you can see here is my spare tire. Okay and there's four connectors and basically, each connector has a little tab and you can see that one right there. Push on the tab and then work the connector off and do that for each of them. Right here, where my finger is pointing, there is a 13mm bolt. You want to remove that bolt and then the plate comes off with that connector. Just a quick tip; we did spray the back of this bolt with penetrating oil. It actually appears to come out pretty easily. There it is out. Now to get this out of the bracket, we are going to take one screwdriver and put it in here - actually in right next to that slot, so that slot is now unlocked. That tab right there that is part of the plastic. Okay, the metal is not holding anymore. And then use another screwdriver and kind of pry it into there. Once you move it a little bit, you can take this screwdriver out and then with this screwdriver, just force it out of the bracket.
And the new one from 1A Auto, you can see that it is exactly the same. They are all - labeled: brown, grey, blue, and the black. Okay and also these tabs make it so you can't connect them incorrectly anyway. So you just place it back into this, okay. Clip it back in place and you are ready to reinstall. You are going to hook your, you have to hook these tabs in first, which means you have to put them in like that and then turn it. Then start your bolt. And I am going to cheat a little bit and bring in the air ratchet, the blue one is up here and it goes on the left, the black one, the gray one goes on top, okay brown or red on the right side and the black one on the bottom.
We hope this 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 are the company that serves you on the internet and in person.
Tools used
Hammer
Flat Blade Screwdriver
1. Removing the Junction Block
Push in the tab and remove the four the junction block harnesses
Loosen the tabs on the junction block with a flat blade screwdriver and hammer
Slide the junction block out by hitting the side with a flat blade screwdriver and hammer
2. Installing the New Junction Block
Slide the new junction block into the bracket
Reconnect the four color-coded junction block harnesses
Secure the bracket clips with a flat blade screwdriver and hammer
Brought to you by 1AAuto.com, your source for quality replacement parts and the best service on the Internet.
Hi, I'm Mike 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 taillight junction block on this 2002 Chevy Suburban. It's the same part and similar process on the Suburbans from 2002 to 2006. You'll need a new taillight junction block from 1AAuto.com, a flat blade screwdriver, and a hammer.
Your taillight junction block is located right here. You want to start off by just pushing the tabs on each of these harnesses and disconnecting them. Most likely, your junction block won't just slide out now on its own, so what we do is we just use a flat blade screwdriver and a hammer to kind of loosen up these tabs. There are four of them in total. We'll just fast-forward as Don does that last tab, and then from the side of the junction block, you want to just use that flat blade screwdriver, hit it with the hammer, and it'll start to slide out. Once you get it most of the way you can pull it the rest of the way out.
On the left is the old junction block; on the right is the new one from 1A Auto. You can see they're identical, and they'll fit exactly the same. Take your new junction block and just slide it into the bracket. Then reconnect your four harnesses. You'll see on the junction block which color goes where. Now, since we've loosened this, it will slide out. Just to make sure it doesn't, we just want to hammer the edge there until it kind of bends down over the junction block. Now it's held in place, and you're all set.
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.
923-012
In Stock
Product Reviews
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4.72/ 5.029
29 reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
24
4
0
0
1
Perfect Fit
Henry
July 2, 2017
They Sent It Really Fast To Me I Had A Back Up Light Out This Fixed My Back Up Light That Was Out Also It Was A Perfect Fit
M
September 11, 2017
Exactly as advertised. Was a perfect fit from the factory replacement.
Great product
R
October 3, 2017
Great product, good quality, easy installation !!!!!!!!
Junction block
Michael
March 25, 2018
Product was delivered fast and came just as advertised. Thanks so much!
M
April 5, 2018
Received quickly and part fits perfect will order from you guys again any day and have already recommended you to friends and family
faulty
George
July 7, 2018
unit did not work properly , my mechanic had to troubleshoot and then by pass the wiring on one side
good service, another happy camper!
shelley
August 17, 2018
Just the piece I needed, and fast delivery service was a bonus. I would recommend your 1A auto parts supply store to all my friends. We were able to change the part and head of on our holidays in record time. Thanks for being reliable
K
September 4, 2018
Product fit and work as it should delivery was on time and I'm very happy with the company
Problem Solver for Truck and Trailer Lighting
O
September 10, 2018
I've had issues with truck electrics on my 04 Silverado and use it to haul a 3 horse Sundowner gooseneck trailer. This part came to my attention via an email from 1A Auto. The information in the email seemed to describe some of the issues I was having with my truck. And of course, there was a YouTube video from 1A Auto that showed how simple this repair is to perform. Ordered the part, usual speedy delivery, problem solved!
Great Price. Gsst Shipping
Julius
November 6, 2018
The price for my part was the best I found. The part came fast. Best of all it was a perfect fit.
Excellent all the way around.
Thanks!!
quick and easy transaction
KIRK
November 30, 2018
Ordering from 1A Auto was easy and received the part quickly!
Direct replacement
Dillon
February 11, 2019
Replaced the factory junction block flawlessly. Only issues I ran into had nothing to do with this part. My driver side tail light/brake like stopped working and new bulbs didn't fix it. Best price on the internet for this piece and it's actually quite a simple job thanks to their tutorial videos.
Alvin
May 15, 2019
Piece of mind when dealing with these guys.
Easy-Peasy
John
July 16, 2019
The part was spot on. The easier way to change is just slightly flex the metal compression tabs and remove one screw. It slides out nicely and lets you clean the frame behind it. Reverse the process to reinstall, put the plugs in their respective spots and your done. Works great.
Satisfied customer
Joseph
August 9, 2019
Works perfectly
Great product
Billy
August 13, 2019
Great price, easy to install.
Tail light junction box
Daryl
April 2, 2020
Fit perfectly fixed problem and installation video was spot on
Thank you
Great product
Eugene
November 7, 2020
Great prices as well. Looked all over and couldnt find this anywhere
Did its job
Austin
July 14, 2021
Replacing this was very quick and easy.
Simple plug and play
Trailer lights
billy
November 29, 2021
Just what I needed to fix my trailer light
Great quality
tyler
January 9, 2022
This item fit As should no issues and fast shipping my old one had corrosion on all the connector pins causing me to lose brake lights
James
February 11, 2022
Thats perfectly and I had no issues
Direct replacemenr
J
March 20, 2022
A direct replacement,
Block
Alan
May 4, 2022
Works good
Eric
September 13, 2022
It was probably the correct part and I switched it out hoping for an easy fix. But didnt fix the problem. Part was as advertise n arrived quickly.
Fixed my Issue!
Jeff
May 2, 2023
I had a 2011 Chevy Silverado 3500HD that had issues with the tail lights. When the running lights were on all tail lamp lights were illuminated but dim. When I activated my brakes, the left tail lamps would all go out and the right would illuminate all 3 lights including the reverse light. I cleaned the connections and it worked for a little while then the same problem happened. I replaced this part and now everything works perfect! Easy to install and 1AAuto's installation video was spot on. Much better than others on the internet. Thanks!
Good product. Exactly what I needed.
Brice
October 15, 2023
Arrived in a couple days, easy to install and did what I needed.
Richard
July 16, 2024
Quality a tad shy of OE. Fit, which it should as a "given"! Functioned as it should. Now the test of time needs to pass. The original was still functional and was replaced due to minor cracks that would lead to random issues.
John
October 7, 2024
as described arrived on time
Customer Q&A
stop light on trailer connects to it too ?October 24, 2015
Donald C
10
Donald, I have not installed it yet. I wrecked the truck and just gotten it back from repairs. You may have an answer before I complete the job.
Let me know what you find out.
Lincoln W.
October 24, 2015
Lincoln W
10
Junction box
October 24, 2015
D O
10
If your truck has the factory trailer connects, it should.
October 24, 2015
Dale G
10
BElieve it does. 4 plugs. 1 for left 1 for right 1 coming front of truck. 4th should be 7 wire rv plug.
October 24, 2015
William R
Can this junction box cause issues with lights on my camper?June 4, 2017
Jared F
10
Fixed my right truck taillight and same side 5th
wheel taillight
June 4, 2017
James L
10
Yes if the contacts are corroded. I would check the receptive on the trick side first and work your way forward. I just spent hours t-shooting mine to find the contacts in the 7 pin recepticle we're corroded
June 5, 2017
Michael I
10
This is possible as the power to the turn signals for both truck and trailer are combined.
June 5, 2017
Alex P
10
hello
i don't have a camper, i have Chevrolet Silverado,, this junction box fixed my rear light issue
June 7, 2017
Miguel P
Does this junction block have anything to do with trailer lights?June 14, 2017
Colton M
10
Not really sure. Friend was having issues with thier taillights.
June 14, 2017
Gregorio M
10
Yes. All the rear lights plug into the junction block.. each connection has uts own tab configuration so they can not be mixed up...you can find the block mounted with one screw on the cross member of the frame anove the spare tire..
June 14, 2017
David D
10
Yes, all of the power to the rear lights will travel through this block.
June 14, 2017
Alex P
10
Iam not sure because i no longer have a trailer
June 15, 2017
S M
10
All the rear lighting passes through the junction block. if it fails NO LIGHTS!
June 16, 2017
Daniel N
10
not realy but a convenient place to check fore voltage
June 22, 2017
David M
Do you have a wiring diagram for the feed wires to this block?March 2, 2019
Brian T
10
We do apologize but we do not have the wiring diagram.
March 2, 2019
Corey M
Does replacing this tail light junction block fix a rapid blinking signal light ?October 26, 2020
Blake B
10
There could be multiple reasons why you're having this particular problem. We suggest taking your vehicle to a nearby reputable shop to identify the cause. Once you know the cause, we'll be happy to see if we carry the parts and how-to videos needed for your repair.
October 26, 2020
Emma F
My 03 Silverado 1500hd L Rear Tail lamp won't come on, changed the bulb, flipped the bulbs, checked the fuses, Break light comes on, side running/blinker only works on blinker mode not running mode. Checked lines for cracks or cuts, zip. Checked thJanuary 7, 2021
Dani D
10
There could be multiple reasons why you're having this particular problem. We suggest taking your vehicle to a nearby reputable shop to identify the cause. Once you know the cause, we'll be happy to see if we carry the parts and how-to videos needed for your repair.
January 7, 2021
Jessica D
Would this have anything to do with my rear parking sensors? They dont work and Ive tried everything except this? ThanksApril 7, 2021
Jon J
10
This is the junction block for the lights, so they would not have anything to do with rear parking sensors.
April 7, 2021
T I
Can I hook up trailer lights w a plug to this box?August 16, 2021
Terry H
10
Yes, the box has all the connections for the rear light connections, including the trailer wiring harness. My truck already had a trailer hitch and electrical connection for the trailer installed at the factory, so it was a simple matter of just plugging in the existing trailer wiring harness into the new junction box.
August 16, 2021
E K
10
Yes
August 16, 2021
John F
Will this junction box fix issues with the third brake light not working?January 9, 2022
John D
10
More than likely they have an led style third brake light and the whole light assembly must be replaced its a very common issue with them going out however if they unplug the wire connectors from the junction box and its severely corroded I would start there a junction box is by far cheeper than the led third brake light assembly
January 9, 2022
Tyler B
10
This junction box is for the tail lights only, not the 3rd brake light.
January 10, 2022
T I
10
No it will not. This junction box is mounted in the rear of the truck, above the axel and has nothing to do with the third brake light. Good luck.
January 16, 2022
Mike L
10
No it will not. This junction box is mounted in the rear of the truck, above the axel and has nothing to do with the third brake light. Good luck.
January 16, 2022
Mike L
Does it come with steel bracket?March 20, 2022
Antonio M
10
No it does not. Unless yours is actually broken or severely corroded, check both sets of fuses before purchase.
March 20, 2022
J C
10
No it does not
March 21, 2022
Lance M
10
No this does not come with a steel bracket.
March 21, 2022
T I
Do you offer the mounting bracket as well?June 14, 2022
Gerry M
10
We do not offer the mounting bracket.
June 14, 2022
T I
I have a 2002 Suburban that has an issue a the plug harness not having ( or sending) the right brake light signal or turn signal. Does this part feed that signal? All other lights and signals are being sent through the plug at the rear of the truck, November 8, 2022
R E
10
There could be multiple reasons why you're having this particular problem. We suggest taking your vehicle to a nearby reputable shop to identify the cause. Once you know the cause, we'll be happy to see if we carry the parts and how-to videos needed for your repair.
November 8, 2022
T I
Customer service
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GMC is a registered trademark of General Motors Company. 1A Auto is not affiliated with or sponsored by GMC or General Motors Company.See all trademarks.
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