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Your Auto Inspector
Your Auto Inspector, Assistant Service Manager
Category: GM
Satisfied Customers: 874
Experience:  ASE Certified Parts and Service Specialist
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2000 gmc Envoy: third brake light..the small roof mounted light

Customer Question

how do i find a replacement third brake light for a 2000 gmc Envoy that goes over the back glass, not on top of car. Also, how do I remove the light? Can the small roof mounted light replace the bigger LED light, perhaps?
Submitted: 7 years ago.
Category: GM
Expert:  Your Auto Inspector replied 7 years ago.

Thanks for using Just Answer. I will be glad to assist you.


Please refer to the diagram below and let me know which style of light you would like.



Customer: replied 7 years ago.
I don't think any of these images are the right one. The third brake light is wide, inside a black plastic casing, and sits on the top of the glass window of the back tail gate door. It is not the shorter one that is common and is mounted on top ot the car. Pep Boys told me the only place to find a replacement is from GM parts for $600.00. They suggest I try junk yards, which I have, unsuccessfully, so far.
Expert:  Your Auto Inspector replied 7 years ago.

In the diagram, the wide light is listed as #1 and sits on top of the glass window on the back tailgate.


Here is a link to one for sale on ebay. The $57.95 price will definately save you some money. You can verify that this is the correct part in the picture below.




Customer: replied 7 years ago.
I already purchased that one from Ebay and it is the one the fits on top of the car. It even says so on the website. I am still stuck.
Expert:  Your Auto Inspector replied 7 years ago.
Can you measure the light and tell me how long it is?
Customer: replied 7 years ago.
Okay, I will be back in a few minutes.
Expert:  Your Auto Inspector replied 7 years ago.
Ok, I will wait for your answer.
Customer: replied 7 years ago.
the black plastic housing that contains the third brake light measures about 44 1/2" and sits on top of the window on the back gate. The light inside seems to measure about 17" showing through the black plastic housing, and if I wedge my fingers underneath the plastic, the entire bulb seems to be about 22".

The replacement bulb I got from Ebay measures about 16" total, and 13" of light. These are definitely two different things.
Expert:  Your Auto Inspector replied 7 years ago.

Here is a link to the other style of light also available on ebay. The light is seperate from the black plastic housing. You will remove the housing and put the light inside it.


This light measures around 21", please refer to the diagram and link below:




If this is not the correct light then I will need your VIN # XXXXX I can find it on a parts locator.

Customer: replied 7 years ago.
This looks like it might be it. The dimensions sound closer. Now, how do I remove the black casing. I have not figured that part out.
Expert:  Your Auto Inspector replied 7 years ago.

It should be held together with screws from the back of the housing.


Have you removed the entire housing yet?

Customer: replied 7 years ago.
No, I could not see any screws. I though that it might snap into place. I did not want to brake anything.
Customer: replied 7 years ago.
by the way, where would i find the vin number?
Expert:  Your Auto Inspector replied 7 years ago.

The vin# XXXXX XXXXX the driver's front of the dashboard if you are looking through the windshield from the outside of the vehicle.


You could also find it on your insurance card.

Customer: replied 7 years ago.
here is my vin number 1GKDT13WOY2214103

Can you double check that this is the right part, so I don't order the wrong part again. And, I am still not sure how to remove the plastic casing.
Expert:  Your Auto Inspector replied 7 years ago.

My diagram shows that the plastic housing comes apart with 2-4 screws from the front of the plastic housing.


The plastic housing definately comes apart because GM used to offer the LED light bar seperate from the housing.


Unfortunately it is more expensive now because you have to purchase the whole assembly. The LED light has been discontinued as a seperate part.




I have found the entire assembly online for $458.98 at


You will have to enter the part # XXXXX into the upper left corner where it says search.

Customer: replied 7 years ago.
so, you are saying to forget about the part from Ebay that you showed before, and I, instead, need to get the whole housing, for $458.98. Is that correct? If it is so, is this something I can do myself?

This is a dumb question, probably, but, could I just somehow use the different light that I already purchased in someway, or would that not work, or pass inspection.
Expert:  Your Auto Inspector replied 7 years ago.

The one on ebay should be the correct one. You will just take the housing apart, remove the old light and put the new light into the housing.


The light is 17 1/4" long and the total unit is 21" overall.


I cant verify that this is the correct part because GM has discontinued the replacement lamp, however i think that it will work.


You can make the other one work with some modification. You would just need to figure out a way to mount the light inside the black housing.

Your Auto Inspector and other GM Specialists are ready to help you
Customer: replied 7 years ago.
okay, i will give the ebay one a try. it sounds like you are saying that I do not need to spend the $460.00 for the entire assembly, and maybe I can jury righ the bulb I have.

thanks for the help.

Expert:  Your Auto Inspector replied 7 years ago.

Your very welcome.


The one on ebay should be the correct one according to the measurements you gave me.


Please let me know if there is anything else I can do to assist you.