Help! Cable through firewall?

[ekolpack]

Trying to run some 4awg wire through the firewall on drivers side and running into a rubber gasket thing. I have access through the grommet/gasket on the engine bay side(removed e-tape) but can't figure out how to get through on the interior side without puncturing the gasket. Here's a video showing the dilemma. Please help! Thanks!

 

[HSTexan]

I actually just installed my Switch Pros this past weekend and faced the same dilemma of getting through the firewall. If you look at it from the engine bay side you should see a nipple in that same grommet. From the engine bay that nipple will be located at the 3 o'clock position on the grommet, nearly opposite from the wire you pointed out in your video. What I did was cut the tip of the nipple off, then attached a heavy duty zip tie to a shoe lace and stuck it from the engine bay side through the nipple and fished it out from the footwell side, I taped the shoelace to the wires I was trying to run, then slathered the tape in soapy water and it slid right through. The issue is that from your viewpoint in the footwell the nipple hole is at the 9 o'clock position which makes it near impossible to see and you really have to rely on feel which is why it's easier to come in from the engine bay side.

 

[kcjaz]

You have to punch or poke a hole through the grommet. I wondered the same thing. Firewall wire penetration - stupid question - https://forum.ih8mud.com/threads/firewall-wire-penetration-stupid-question.1286942/ See video in post #8 from @nakman.

@HSTexan I don't understand how you got your zip tie through without poking a hole.

 

[HSTexan]

You have to punch or poke a hole through the grommet. I wondered the same thing. Firewall wire penetration - stupid question - https://forum.ih8mud.com/threads/firewall-wire-penetration-stupid-question.1286942/ See video in post #8 from @nakman.

@HSTexan I don't understand how you got your zip tie through without poking a hole.

I cut the tip of the nipple off where you have the white and red/black wires going through in your link, when I did that I was able to push the zip tie through. I could feel a hole on the inside footwell where the nipple was.

 

[ekolpack]

Yeah I saw the long nipple thing on the other side when I removed the e-tape. It's too small for 4awg, especially if I add split loom, but will work nicely for some other stuff I have planned. I'll do as suggest by kcjaz for the 4awg and try to seal it up as best I can (maybe that Flex Seal stuff on a long straw?) Thanks fellas!

 

[rlynch356]

I just ran 4ga though the drivers side gasket.. cut the tip of the nipple off, run a smaller wire through (12ga or so) - then tape that to the 4ga wire, apply some dielectric grease to the leading bit of the 4ga wire and pull it through gently. you don't need a lot since it will coat the inside of the nipple and help slide it though and provide some sealing afterwards as well.
Use loom after you get it though the nipple on either side of the bulkhead, the gasket/nipple will be fine for that section. Or if you worried about it, heat shrink (marine adhesive high quality type) the section that actually goes through the fire wall gasket. I used braided split loom for the rest of the run front and back.

 

[SF1911A1]

I haven’t even tried yet, but I have some zero guage wire to run to the back to set up a power station. Any suggestions for an alternate route or is this the best way that y’all know of?

 

[kcjaz]

I cut the tip of the nipple off where you have the white and red/black wires going through in your link, when I did that I was able to push the zip tie through. I could feel a hole on the inside footwell where the nipple was.

Interesting. I could not find a hole. I had assumed there would be one but if it’s there, I couldn’t find it.

 

[rlynch356]

Its there.. once you cut off the tip of the nipple.. use a strong zip tie as a feeler..

0 gauge is probably best routed under the along the frame, and come up though one of the 2 rear grommets, you will have to cut a slot.... then seal it.

But why 0 gauge? most DC/DC chargers max out at 40-50amps, and unless you are running 300amps+ of lithium I can't see the need for more.
I am running a 40amp Redarc DC/DC using a 4ga cable, which is over spec'd for the distance of the cable run, which is maybe 15ft..

 

[SF1911A1]

Primarily a better safe than sorry attitude. Considering running a 1500-2000 watt pure sine wave inverter in the nearish future, but for sure a 12v power station soon with a 3 dc connections, an Anderson connection and USB port to begin with.

 

[ekolpack]

I just ran 4ga though the drivers side gasket.. cut the tip of the nipple off, run a smaller wire through (12ga or so) - then tape that to the 4ga wire, apply some dielectric grease to the leading bit of the 4ga wire and pull it through gently. you don't need a lot since it will coat the inside of the nipple and help slide it though and provide some sealing afterwards as well.
Use loom after you get it though the nipple on either side of the bulkhead, the gasket/nipple will be fine for that section. Or if you worried about it, heat shrink (marine adhesive high quality type) the section that actually goes through the fire wall gasket. I used braided split loom for the rest of the run front and back.View attachment 3057701

Wow, huge help! Thanks! Lie @SF1911A1 I'm also running 0awg to a rear "main panel" as it were. I plan on doing the KISS dual battery setup (thread can be found on this forum) which uses dual deep cycle lead acid batteries under the hood and no BCDC. I'd like a 1500-2000W inverter, along with a few other things (sub amp, cooler, anderson plugs, misc) and the ability to potential add a LiFePo4 with BCDC at some point in the future if I want. This means a pretty hefty potential current draw from the front. It was recommended in another thread to run the 0awg through the little firewall hole, but it seems like down along the frame and up through a quarter panel is probably a better idea. Aloha!

 

[Julian73]

Its there.. once you cut off the tip of the nipple.. use a strong zip tie as a feeler..

0 gauge is probably best routed under the along the frame, and come up though one of the 2 rear grommets, you will have to cut a slot.... then seal it.

But why 0 gauge? most DC/DC chargers max out at 40-50amps, and unless you are running 300amps+ of lithium I can't see the need for more.
I am running a 40amp Redarc DC/DC using a 4ga cable, which is over spec'd for the distance of the cable run, which is maybe 15ft..

While I agree that 0 AWG is overkill for most everything, one must be careful to size wires based off voltage drop on these low voltage (12VDC) systems. 50 amp loads in a bundled harness, not subjected to engine bay temperatures, will need to use 4 AWG for run lengths (including the return leg to battery) of 25 ft or 2 AWG to 40 ft ... that is a total 20 ft distance from battery to load.