How to add cab lights to a 2020+ Silverado

hotairgypsy · April 10, 2021

This first think i did was mask off all the area I was going to work so i can reduce the chances of scratches and i could also write on the tape all i wanted.

Then i got the lights and made templates of them so i could place on the truck as per the measurements.

Here is a tip to use when you are further in the installation...The screw there is a 10MM..The way it is designed is when you pop your lights thru the roof you crank down the 10mm and the 4 legs spread out against the underside side of the roof sucking down the light to the roof. I had a hard time with that so what I did was unscrew the bolt and took off the legs...After i popped on the lights thru the holes I reattached the screw and legs from the underside...BUT before I did that i spread the legs to roughly 45 degrees...This helped me not have to fight the securing the light due to the tight area and helped me work around any sanding i had to do to get the light to seat.

Thanks to SEFTON i got a great jump on the measurements I needed to place the templates in the proper area...I also got access to a new 2021 for a few minutes and went over all the measurements for any adjustments. There was some adjustments i did make to this on the fly...the 12 inch measurement is actually a bit over 12 1/8...The 8 3/8 is also a bit over...i was just splitting the difference to get the center light centered. When placing my templates I used a digital caliper so this is why you see the decimal equivalents.

The is when i got my templates in place as per my measurements.

Once i got my templates in place i used a center punch on all the centers...then i predrilled with a real tiny drill bit...then i got a middle size bit and drilled the holes...after that i drill the main holes with a 27/64th drill bit...once the hole was drilled i did intentionally wobble the drill bit in the hole to slightly widen it so the punch tool would have a tight fit to stay centered...I never tried the next drill bit bigger because I wanted to slowly work my way to the tightest possible fit...

Once i got the 27/64 holes drilled i used the greelee tool i had bought to cut out the 3/4 square holes i needed to cut out for the installation...here is the tool and how it breaks down.

I just used a 1" wrench with the tool to cut out the holes...very easy tool to use..there is lines on the side of the tool to line up so you can align you square hole.

took less than 10 turns to complete the job

i would test fit the lights at this point to see how much filing you need to do to help out the fit...you can see one of the 4 alignment marks on the tool I used to line up with my marks on the tape to make sure the square the clocked properly ....once test fit was good i pulled the tape and you can see what the hole looks like before the light is installed.

once all 5 holes were done you can see what you are left with here...i cleaned out the tool after every hole was punched.

At this point i ran the harness and got everything plugged in...There are holes predrilled for all the fasteners so once you plug in the harness to the truck just aligned the fasteners to the holes and your done real quick...factory plug is in the driver pillar up towards the top. Harness just plugs in..

above pic before plugging in..below pic is once I plugged the harness in.

Once I got all secured down and plugged in I just activated the remote to test the lights and here is it with the new cab lights.

Yes there are steps to working this the headliner in side...The next post with cover generalities of what you need to do to get to the underside of the roof.

hotairgypsy · April 10, 2021

So this pic is the backside of the center light center attachment point so you can see what is looks like after it was screwed down

How i got access on the inside was my own way due to having a sunroof...I cannot speak for headliner removal without sunroof. So if i was doing this over again I would first remove the side pillar cover that covers the front seat belts...It has 2 10mm screws and a 7mm screw to be removed. There are a couple of clips holding the panel in place. just pull towards the interior and they will come off easy.

i just placed the covers in behind the front seats just out of the way. next you need to pull down the rubber door gasket on both sides and I just let them droop.

The your off to the window pillar covers on both sides...once you get to two covers off there will be 2 10mm screws on both sides...there is a really strong clip holding the panel on so you will have to pull on the upper part in towards the stereo...they are really grabbing on...i broke one side removing it. you can see the clip in one of the following pics.

you can see the clip in this pic...it is right next to the yellow sticker

Next i would remove the overhead console light assembly. It is 2 little covers you pop off and then remove 2 T15 screws that are in the round holes.

next it is sun visor time. There is a cover covering the screws at the hinge part..You will need a T15 torq for visors and the center overhead housing...following pics so it disassembled. Worst part of it is the harness that is plugged in. GM glued the harness to the headliner...you will have to reach under it and rip the harness off the headliner so you can get it to the hole to unplug the visor. it is a pain. Take note of the white ring thing and how it is positioned...It is just clipped the visor so you will have to pop it off

above pic is just after visor removed with white thing in place. Lower pic is the individual parts

The clip that the visor clips into just has an access door to be opened and then a single T15 screw to be removed.

here is just a general pic of the visor mounting plate

.

well at this point I just worked my hands in there and did all the work...i didnt want to a disassemble my sunroof so i just worked around it. If you dont have a sunroof then you probably have lots of room at this point...let me know if you have any other questions and I can fill in the blanks...obviously you just reverse the above instructions to put it all back together.

Edited April 20, 2021 by hotairgypsy

Limelight · April 10, 2021

Man great job! I’ve done a TON of writeups on another forum I was on and I know how much time it takes.

This is excellent and a great contribution to this forum.

THANK YOU!

motorsswin · April 10, 2021

Great write up. Any need for silicon or anything like that or do the lights have a rubber gasket to seal to the roof?

hotairgypsy · April 10, 2021

2 hours ago, motorsswin said:

Great write up. Any need for silicon or anything like that or do the lights have a rubber gasket to seal to the roof?

the lights come with a foam liner on the bottom .there is even double thickness right around the mount...i didnt get a pic of that but someone else can upload down the road to the thread.... i tried silicone for the middle one bit i may land up redoing it cuz i think my silicone may have been bad...at least if i have to redo it i only have to drop the center housing and i can get to all the bolts i hope

Edited April 10, 2021 by hotairgypsy

KTDanforth · April 12, 2021

Just wanted to say great write up. The rest of my kit is arriving this week. I like the idea of using a hole punch vs using a dermal. I think I will reach out to my local auto parts stored to see if I can rent one.

Again Well done!!!!

Limelight · April 12, 2021

On 4/9/2021 at 10:09 PM, hotairgypsy said:

This spot is reserved for the interior headliner work i am going to show you ...so stay tuned here

Any progress on this part? I would love to see how you accesses the inside.

thanks!

maine shadow · April 16, 2021

I know the OEM cab lights that are installed after vehicle purchase are only available for HD models.

My question is will the wiring harness that fastens to the trucks electrical supply be the same for a 1500 series.

I would like to install GM cab lighting rather than after market on my 1500 but question if wiring would be compatible.

Any help??

BTW, great write up.

KTDanforth · May 16, 2021

Just wanted to say thank you, just competed the installation this evening. You saved me a lot of hart ache. I did go with the Greenlee, I found an older model #731 but new unit for under $100.

Thanks again

Edited May 16, 2021 by KTDanforth
added model number

Biebs · November 10, 2021

Amazing post. You are the only one! .. I know you kinda answered this, but if you were to redo it.. you WOULD use good silicone on all of them? Or would you just use the foam double padding they have?

Stand By · November 11, 2021

20 hours ago, Biebs said:

Amazing post. You are the only one! .. I know you kinda answered this, but if you were to redo it.. you WOULD use good silicone on all of them? Or would you just use the foam double padding they have?

If I do this mod, I'd probably either use a tiny brush and paint the bare metal edges or even paint on a thin layer of epoxy over those edges. Can't imaging having a bit of the silicone being pushed away during the install and being exposed if the foam gasket breaks down later.

Biebs · November 13, 2021

Gotcha! I appreciate it!

Biebs · November 15, 2021

On 4/16/2021 at 2:43 PM, maine shadow said:

I know the OEM cab lights that are installed after vehicle purchase are only available for HD models.

My question is will the wiring harness that fastens to the trucks electrical supply be the same for a 1500 series.

I would like to install GM cab lighting rather than after market on my 1500 but question if wiring would be compatible.

Any help??

BTW, great write up.

I opened up a 2020 gmc 1500 - it did not have the factory wiring, right into the pillar like the 2500, but it is possible to run the wire from the harness just would have to make some modifications

Biebs · November 15, 2021

Here are some pictures of the interior part if needed :

Biebs · November 15, 2021

Side note, the Square holes are 100% necessary for the stock clips to work and pull it tight so follow his steps exactly and rent/buy that tool if you can

the clips (I’ll add a photo) have little pop outs that clip into place but only a square will do.

If you absolutely can’t get that tool or rent one and can’t dremel a perfect square, I’ll post another on a suggestion