ANZAC

I tried to post in the write-up section and it wouldn't let me.

Anyway, I needed to run some wires through the firewall. There is a bung to the left of the brake booster which can be pushed out, revealing a 1.5" hole.

After you clean the foam off it, it is difficult to find a nice grommet that will fit it.

I found this grommet off a Subaru, which is a perfect fit for the hole.

Now, I didn't really like the wire exit, and wanted something a little more watertight, so I took a Daystar firewall boot
(which at 1.25" is too small to use by itself) and cut off part of it and glued them together with E6000 glue to make one franked-grommet.

The nice thing about the Daystar boot is you can use a zip-tie on the end to sea it, and add more wires later by replacing the zip tie. If you need even more wires, you can cut a section off to reveal a larger hole, and still zip tie it. The perfect solution would be if Daystar made a 1.5" boot, but the franked-grommet is a good solution that will seal well.

The factory bung I removed is shown on the right.

Fred/N0AZZ

You can buy new ones at most all auto parts stores in all sizes.

ANZAC

They would only be a flat grommet which you'd poke a hole through and slob some RTV on. This will give a better seal and you can add more wires as you go.

Anyway, you don't have to use it if you don't want!

Fred/N0AZZ

What ever floats your boat I guess, I fit the hole to the wire size and then use the correct grommet with it, instead of a one size fits all.


I know about the bungs have used them in the past but drilled a hole in the center for the wire/grommet size needed, only removed if there were a very large or number of wire's to pass through.

ANZAC

In my case I have many wires to pass through, over a period of time. I don't want 10 small holes in the firewall. I need a setup that is flexible and expandable. I also liked the idea of using the factory hole rather than drilling.

moparado

I've run a few 16 ga. control wires over the years through the firewall using the existing large cable grommet near the master cylinder.
Fished the wires through that cable grommet right next to the existing cable.
In my case, the original cable/grommet sealant gave way easily enough to do this.

Cleaned the whole works with aclahol then gooped on a 'little' silicon sealant.
Did the same a few years later for my elec. fan delay timer switch wire.
So definitely expandable.

If you need to run much more than a few or heavier ga. wires than this probably might not work.
But then again heavier ga. hi amperage wires typically require a relay somewhere in the engine bay.

ANZAC

Yeah, I was running 4 wires, but maybe more later:
- rear e-locker pair
- to driving light relay
- 12ga from 20A breaker for brake controller