Page 1 of 1

Size of hole in roof for rooftop lightbar?

Posted: Thu May 26, 2016 4:41 pm
by CrashTestDummy
Does anyone know, or can anyone measure the hole cut in the roof for the rooftop lightbar? We have a plug in ours, and I'd like to make sure I can cover it when I pull that plug. I'm actually contemplating getting a working GPS antenna for that spot, for any potential future use, so also want to make sure I don't get something too small, or too large. I got an old, used GPS pancake antenna from Garner, but am really thinking that if I'm up in there, I might as well snake some coax down the B-pillar, too. Just a thought. The old antenna was for the price of shipping, a new antenna is some $$.

Thanks.

Re: Size of hole in roof for rooftop lightbar?

Posted: Thu May 26, 2016 6:56 pm
by smwalker
Do you think those are a standard size? Or did every upfitter use what ever size they wanted/needed?

Re: Size of hole in roof for rooftop lightbar?

Posted: Thu May 26, 2016 7:37 pm
by elc32955
It greatly varies depending on what tools the installer had handy at the moment. No easy way out of that one I'm afraid, your cable hole is individual to your car. Sorry.... I've seen installers use antenna hole saws, cable hole saws with different diameter, you name it. If the blade gets dull on saw "A" they just switch to different diameter saw "B" and grab escutcheon "B" instead of "A" for the remainder of the installs for the day.

Ever seen an equipment install that prison inmates did? :) Heh heh....

Re: Size of hole in roof for rooftop lightbar?

Posted: Thu May 26, 2016 11:14 pm
by CrashTestDummy
Okay, the 94-96 B-body cars had a standard hole with a harness pulled through it from the assembly plant. I figured it would still be a standard. My bad.

Re: Size of hole in roof for rooftop lightbar?

Posted: Thu Mar 09, 2017 5:58 pm
by CrashTestDummy
I used a large washer to back up the mounting nut on a GPS antenna. Everything went together fine.

And yeah, the hole was pretty narly-looking. Probably drilled with a hole saw that was way past it's prime.

Re: Size of hole in roof for rooftop lightbar?

Posted: Thu Mar 09, 2017 7:07 pm
by BIG_GREEK
yea it all depends. If the hole comes from the manufacture (Factory option), its most likely 3/4"-1". It can vary depending on what lightbar was used, what the moron was thinking whilst doing it, etc...

If in doubt, pull the plug, measure the hole and reinstall plug with silicone sealer.

Re: Size of hole in roof for rooftop lightbar?

Posted: Mon Apr 03, 2017 1:56 pm
by CrashTestDummy
IIRC, it was about 1" in diameter. A large flat washer served well to back up the nut on the inside.

Re: Size of hole in roof for rooftop lightbar?

Posted: Thu Jul 05, 2018 6:36 pm
by StevenJay
Measure it, but standard is 1 inch

Re: Size of hole in roof for rooftop lightbar?

Posted: Thu Jul 05, 2018 6:41 pm
by StevenJay
If it was a lightbar hole upfitters will just drill a 1 inch hole, install a rubber 1 inch thin wall grommet and run the wire bundle through the hole and silicone it .