Firewall pass-through for power supply on 7MT.

[RossBG83]

If you cut the nipple on the grommet in the engine bay it's a 1/4 in hole.

What I ended up doing was using an X-acto knife to cut an X on the left side of the grommet in the engine bay, then sliced open the right side of the rubber nipple on the right side of the grommet behind the clutch. From there tied off the 3/4 inch antenna connection to a coat hangar and pulled it through. Hope this helps clarifies things for someone.

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[redone17]

I did the same, but be careful - I somehow sliced the fuel gauge wire. Cost me a week at the dealer and a massive headache for the tech. I was throwing codes for everything.

 

[John P.]

If you cut the nipple on the grommet in the engine bay it's a 1/4 in hole.

What I ended up doing was using an X-acto knife to cut an X on the left side of the grommet in the engine bay, then sliced open the right side of the rubber nipple on the right side of the grommet behind the clutch. From there tied off the 3/4 inch antenna connection to a coat hangar and pulled it through. Hope this helps clarifies things for someone.

Appreciate the intel, as someday soon I’ll be running amplifier power wire. Looking at your pics it looks like the wire you ran isn’t any wider than 1/8” or 1/4” unless the perspective is throwing me off. If thats the case, why not use the nipple?

 

[Dads_bronze_bronco]

I was prepping for a powered sub install today. I’ve heard others use a small rubber grommet on the drivers side. On a manual transmission it looks to be used by the clutch. I could poke a hole in the giant rubber wire bundle pass-though but was hoping for another option.

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PDF file if original link doesn’t download for you: https://www.bronco6g.com/forum/attachments/bronco-compressed-pdf.187532/

This may help answer your question

 

[RossBG83]

Appreciate the intel, as someday soon I’ll be running amplifier power wire. Looking at your pics it looks like the wire you ran isn’t any wider than 1/8” or 1/4” unless the perspective is throwing me off. If thats the case, why not use the nipple?

Just to make future access easier, glad I didn't cut anything

 

[redone17]

Just to make future access easier. Probably not the best solution but ¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯

I did the same as you for my GMRS cable and somehow nicked the gas gauge wire. Out of everything in that main harness. No idea. It caused all sorts of issues. But, an overlay and it’s been fine since.

I never got the full story from the tech. I wanted to give him some time to deal with the PTSD. I’ll report back once I know more info. I think there was some other underlaying issues that this brought to light.

I ran amp and IAG dome lights through the nipple.

 

[skim276]

I just cut the nipple off and confirming it is a tiny hole, not enough to run multiconductor cable through, maybe for a single wire or something. Based on the cross sectional diagrams someone posted of the rubber grommet, it looks like it's still sealed from the inside, so cutting the nipple off doesn't seem to compromise the seal. I may have to go the route of cutting next to the wire harness as you guys did, looks like it is much thinner and easier to run cable through. But it doesn't seem very easy to seal off. Are you just putting some electrical tape on it and calling it good? Does anyone know of any grommet/clamp type device that could get a good seal? Thanks in advance.

 

[LevelSeven]

Just successfully installed a Midland GMRS antenna through the ‘nipple’ into the cabin. I did not see it mentioned anywhere in the thread that the grommet can easily be pulled out towards the engine bay. From there you can use an x-acto blade to make a star pattern. Since the antenna was larger than a wire, I also used a drill bit to create more space. If you squeeze the grommet at the top while drilling, you will notice a round ‘protective’ circle on the cabin side - just opposite the ‘nipple’. This should prevent the hole from expanding.

Engine Bay:

From inside the cabin looking up:

Drill in Engine Bay:

I used some marker grease to help move the wire through the grommet and a piece of weed whacker string to easily see it in the cabin:

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