Best way to get through the firewall?

I’ve got four runs of 16 AWG primary wire that I’m trying to pass through the firewall.

The grommet on the drivers side next to the brake booster is the ideal spot and it feels like I can get through an opening on the underside, but it seems there is an inner grommet or something that stops my advances.

Is there a secret to getting through this thing that would save me some effort here?

Referencing a photo from another post, a post which I can’t seem to find again - it looks like they’ve cut into the grommet.

Is it customary to have to cut through an inner and outer grommet, or cut in from a particular place or angle?

https://tnstatic.net/attachments/c3433cc7-6159-4ad8-b1b7-298b288cfcc7-jpg.498289/

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I just found the post I wish I’d seen 30 minutes ago.
https://www.tundras.com/threads/running-cables-through-firewall.12983/

It looks like I can snip and go through the nipple on the underside of the drivers side grommet. Or try to fish something along-side the hood release, but probably won’t be able to get all four 16 gauge wires I suspect.

I’ll give the nipple approach a try - still welcome any comments that will make this a straight forward task.

 

Yuhp.... Snip the nipple and you'll be through; that's the method I've used in my trucks. Just know that depending on what side of the truck you're coming through you may find the 'fishing' part easier to complete if you remove the lower kick panel, etc... on the vehicle's interior. Have fun w/your project!

 

Thank you!

 

If you have any handy, a length of the conductors inside Romex is immensely helpful to fish wires.

They do make pro tools for this type of stuff (known as a "wet noodle" in my profession) but romex works pretty damn well.

 

+1 to copper wire. Also, adding a little dish soap to the end of the wire you're trying to fish through helps as well!

 

I carefully drilled my own hole in the grommet off to the side of the wire bundle and then used a fishing stick. Solid wire works, just be sure to squeeze the hook closed and give it a wrap of tape if you're going to drag it back through your wire bundle. It can be really sharp on the cut end

 

Snip that nipple. Then grease it. If you don’t put some Vaseline or something on there it’s going to catch the cable you pull through.

 

For some reason, I never thought about dish soap...

Water based lube is my go to, especially when pushing insulated wire through rubber

 

Thanks all - I’m going the nipple route - probably hit this on Sunday, just haven’t had time for it this week. Good idea on the grease - a little case sizing goop ought to do the trick.

 

Don’t use Vaseline to lube since it is petroleum based which isn’t good for rubber. Use dish soap or something that is either teflon or silicone based.