cargo light/ 3rd brake light install

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

mxer147

83 K20, 350 vortec, 465, 208, 14/10, 4.10, 33s
Joined
Feb 8, 2023
Posts
950
Reaction score
3,590
Location
Colorado
First Name
Jack
Truck Year
1983
Truck Model
k20
Engine Size
350
What’s hiding behind the vertical panel between roof line and rear window. I’d be bummed if I created extra repairs if I drilled in the wrong spots. Any pics available of the factory installation holes? I’m installing a newer led light, not the factory original.
 

Attachments

  • IMG_0657.jpeg
    IMG_0657.jpeg
    68.6 KB · Views: 39

TotalyHucked

Full Access Member
Joined
Feb 24, 2020
Posts
7,057
Reaction score
26,411
Location
Auburn, Georgia
First Name
Zach
Truck Year
1985
Truck Model
Sierra 1500
Engine Size
5.3
That seam is where the back cab panel and roof panel pinch weld together. So that flange goes straight inward and is about 3/4" wide. Then there's the inner roof structure a little over 1" from the back cab panel. I've thought about doing this myself but not sure I've got the balls
 

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
9,558
Reaction score
17,538
Location
The Right side of Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
What’s hiding behind the vertical panel between roof line and rear window. I’d be bummed if I created extra repairs if I drilled in the wrong spots. Any pics available of the factory installation holes? I’m installing a newer led light, not the factory original.
Do you have a dome light inside? You can see what’s back there. It’s not scary. Measure twice, cut and drill once.
 

mxer147

83 K20, 350 vortec, 465, 208, 14/10, 4.10, 33s
Joined
Feb 8, 2023
Posts
950
Reaction score
3,590
Location
Colorado
First Name
Jack
Truck Year
1983
Truck Model
k20
Engine Size
350
No dome light but I am planning to add one. I now have a headliner which I can use the cutout to locate the drill hole. I’m just not sure what’s behind it such as roof supporting sheet metal layer. There’s a groove on that outside surface and I’m unsure what’s behind it so I was hoping someone would share their experience. Thank you for the response Todd.
 

mxer147

83 K20, 350 vortec, 465, 208, 14/10, 4.10, 33s
Joined
Feb 8, 2023
Posts
950
Reaction score
3,590
Location
Colorado
First Name
Jack
Truck Year
1983
Truck Model
k20
Engine Size
350
No dome light but I am planning to add one as well. Not concerned about the dome light since I now have a headliner which I can use the cutout to locate the drill hole. For the cargo light I’m just not sure what’s behind the panel such as roof supporting sheet metal layer. That cab back exterior panel has a significant groove between the roof line and slider window which I’m not sure if a metal support is behind it. I realize most of the surface will get covered up by the cargo light but I definitely don’t want to drill more holes than are needed since it could be a water entry point.
 

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
9,558
Reaction score
17,538
Location
The Right side of Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
^Ya for sure. Especially starting blind.
@mxer147 maybe someone can get you a pic of the openings. This is the best I got
You must be registered for see images attach
 

Doppleganger

Full Access Member
Joined
May 24, 2019
Posts
14,290
Reaction score
67,351
Location
OH-MI: Just like it sounds
First Name
Chris
Truck Year
1985
Truck Model
K20
Engine Size
5.7
Here they is. Thought about this myself but I just spent 2 yrs getting my roof skin fixed and after hitting my head 27 times (a few were accidents) am preparing to drill 15 holes in it for cab lights. That alone has me hesitant. The last pic is the inside dome light.

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach
 

mxer147

83 K20, 350 vortec, 465, 208, 14/10, 4.10, 33s
Joined
Feb 8, 2023
Posts
950
Reaction score
3,590
Location
Colorado
First Name
Jack
Truck Year
1983
Truck Model
k20
Engine Size
350
Thank you, thank you, thank you….these pics help immensely. When I drill and install, I will take pictures and post for others to see.
 

mxer147

83 K20, 350 vortec, 465, 208, 14/10, 4.10, 33s
Joined
Feb 8, 2023
Posts
950
Reaction score
3,590
Location
Colorado
First Name
Jack
Truck Year
1983
Truck Model
k20
Engine Size
350
Lies. It's always scary to cut on your truck lol
Especially when it’s already painted because I’ve done most of the restoration work in reverse order. I’m planning to create much smaller openings for those lights.
 

Steelbuddha

Full Access Member
Firefighter
Joined
Mar 16, 2024
Posts
146
Reaction score
228
Location
Central North Carolina
First Name
Jonathan
Truck Year
1984
Truck Model
K20 (dump bed)
Engine Size
350
I might be inclined to use a surface-mounted fixture of some type, rather than going for the recessed original equipment design. It's not likely anybody would care about what the light itself looked like. That way you get away with maybe a 1/4" hole for wires and a couple of tiny screw holes, rather than trying to do surgery on the pinch weld and make it look factory. It's not like you'll be entering the Pebble Beach Concours, after all ;) .
 

Johnny Atomic

Full Access Member
Joined
Oct 18, 2019
Posts
190
Reaction score
485
Location
Little Rock AR
First Name
Johnny
Truck Year
1983
Truck Model
Sierra Classic 1500
Engine Size
350

mxer147 what kind of light are you going to use. I'd like to find a way to have cargo, 3rd Brake light, and backup camera in one unit.​

 

quicksilver702

Junior Member
Joined
Nov 3, 2023
Posts
10
Reaction score
6
Location
Henderson, NV
First Name
Ben
Truck Year
1976
Truck Model
C10
Engine Size
400
Someone posted this long ago. I kept it for someday when I add my own.
 

Attachments

  • Cargo light measurements.png
    Cargo light measurements.png
    429.9 KB · Views: 27

HOTFOOT

Full Access Member
Joined
Feb 29, 2020
Posts
542
Reaction score
1,307
Location
northwest ct
First Name
michael
Truck Year
1980
Truck Model
gmc k3500 srw
Engine Size
400
This was my factory light!
 

Attachments

  • IMG_5033.jpeg
    IMG_5033.jpeg
    111.9 KB · Views: 16
  • IMG_5034.jpeg
    IMG_5034.jpeg
    129.9 KB · Views: 12
  • IMG_5035.jpeg
    IMG_5035.jpeg
    118.8 KB · Views: 17
  • IMG_5037.jpeg
    IMG_5037.jpeg
    110.7 KB · Views: 16

Latest posts

Forum statistics

Threads
48,666
Posts
1,074,175
Members
43,338
Latest member
jw23655
Top