Topic: Fog Light wire harness Grommet - 66 GT Mustang Coupe

[Tiny]

Hi all first time user.  Can someone please assist with the ''correct size'' hole for the 66 GT Mustang Coupe Fog Light Wiring Harness Grommet.  My 66 GT has had the radiator support replaced so I want to recreate the correct factory holes for the Fog Light harness wires. I have tried to research the correct factory size holes but I get a lot of discrepancies from various people and suppliers.  Sizes range from, 11/16, 13/16, 3/4 and so on.  Some suppliers say the park light grommets are the same size as the fog light grommet but I don't think this is the case.

I just want to make sure that I get it correct when I create the new holes.  Can someone tell me definitively what the correct size is.

Much appreciated

Mark
Australia

[jwc66k]

Mark,
Welcome to the forum. Depending on where you are in the land down under, you may find some support from others on the forum "down there". I'm in the recently flooded Northern California area.
The fog light grommets were a standard Ford part, C3AB-14603-B (vendor marked "P405), and used a 3/4 inch hole (my notes say 0.729 in dia). Unfortunately, it is not faithfully reproduced. The parking light grommet is C3AB-14306-C and requires a 0.823in dia hole. Whatever you decide to do, get the grommets first, then drill the holes.
Jim

[midlife]

For the non-purist, I agree: get the grommet first, and measure the diameter of the grommet where it fits the firewall.  Drill to that size or a tad over.  Once the grommet is in place, no one will ever know that it may not be exactly the right OEM size, but it will work just fine.

[Tiny]

Thanks all, much appreciated.

Cheers

Mark