Firewall wiring: driver vs. passenger side?

[slim_pickens]

This upcoming weekend, I need to run a 6 AWG power wire from my main battery (2022 Wrangler automatic with eTorque) to the rear in-floor cubby to power my REDARC & auxiliary battery setup.

I know people generally tackle getting cable to the back of the Jeep in one of two ways: (1) running the cable along or inside the frame rails and then up into the cab in the back through something like a drain plug; or (2) passing through the firewall and into the cab. For the sake of reliability and "doing it right" (?), I'm leaning toward the latter unless you guys tell me it isn't worth the hassle.

That said, thanks to plenty of posts on the topic, there are two approaches to passing the firewall: (1) the "easy" route on the driver's side with the unused plastic cap where I think the clutch cylinder on a manual transmission would pass through; and (2) the "harder" route on the passenger side with the grommet high up behind the glovebox that takes a fair bit of fishing, apparently.

I would slightly prefer running the cable along the passenger side of the cab since my connection to the REDARC will end up on the passenger side of the rear anyway. But without having done this before, I'm a little fuzzy on the tradeoffs here between the approaches. Any advice?

Thanks guys.

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[nU7OuxIx]

I ran my antenna wire for my GMRS radio from the engine area into the passenger side. I took a look at where the grommet is on the passenger side and said nope.

From what it looked like to me, you need to remove the fuse box. That's a risk in and of itself. Then you need to cut a little rubber nipple off the OEM grommet that's right above the stock wiring. If you're not careful, you can slice a stock pcm wire. And lastly, the heat pipes run over there that get really hot. I don't know how close they sit to the wiring but they're over there somewhere.

I looked over on the driver side and quickly located the blank plastic piece both inside and out. Even though I have to zig-zag the antenna wire, I chose the path of least resistance and possible damage.

To each their own. The older I get, the more I learn not to mess with stuff when it's not broke.

 

[Some Random Guy]

Are you running CCA or pure copper? 6 AWG CCA will probably be better running through a plug than through the firewall.
If pure copper, then maybe the firewall. I don’t have experience doing the main grommet in the passenger side. I ran it driver side through an unused plug not mentioned in this thread. I have a manual, so the plug you mentioned is occupied for me.
If I had to re-do a plug, I’d do a better job this time of drilling it and sliding it on rather than cutting it with side cutters like I did when I was lazy and frustrated last time.

 

[slim_pickens]

Are you running CCA or pure copper? 6 AWG CCA will probably be better running through a plug than through the firewall.
If pure copper, then maybe the firewall. I don’t have experience doing the main grommet in the passenger side. I ran it driver side through an unused plug not mentioned in this thread. I have a manual, so the plug you mentioned is occupied for me.
If I had to re-do a plug, I’d do a better job this time of drilling it and sliding it on rather than cutting it with side cutters like I did when I was lazy and frustrated last time.

Thanks. I'm using pure oxygen-free copper cable here.

 

[slim_pickens]

I ran my antenna wire for my GMRS radio from the engine area into the passenger side. I took a look at where the grommet is on the passenger side and said nope.

From what it looked like to me, you need to remove the fuse box. That's a risk in and of itself. Then you need to cut a little rubber nipple off the OEM grommet that's right above the stock wiring. If you're not careful, you can slice a stock pcm wire. And lastly, the heat pipes run over there that get really hot. I don't know how close they sit to the wiring but they're over there somewhere.

I looked over on the driver side and quickly located the blank plastic piece both inside and out. Even though I have to zig-zag the antenna wire, I chose the path of least resistance and possible damage.

To each their own. The older I get, the more I learn not to mess with stuff when it's not broke.

There is definitely something to be said for the simpler route even if it is not quite as direct.

 

[Some Random Guy]

Thanks. I'm using pure oxygen-free copper cable here.

I think if I were to try the passenger grommet I would make a cut from each side rather than disassemble everything to use the un-occupied portion. That minimizes the chance of nicking something. Then RTV the crap out of it.
Or find an audio shop to do it?

 

[JEEP4U]

Ran mine on the passenger side (firewall & interior) for RedArc Manager30. Best to remove battery_Fuse box_battery tray...... white arrow points to nipple in wire harness grommet, that I utilized.

See Genesis Offroad dual battery video for removal

 

[hellafools]

Ran mine on the passenger side (firewall & interior) for RedArc Manager30. Best to remove battery_Fuse box_battery tray...... white arrow points to nipple in wire harness grommet, that I utilized.

See Genesis Offroad dual battery video for removal

Sorry, don’t mean to hiJack this thread, but was wondering where you ended up mounting the manager30?

 

[JEEP4U]

I think if I were to try the passenger grommet I would make a cut from each side rather than disassemble everything to use the un-occupied portion. That minimizes the chance of nicking something. Then RTV the crap out of it.
Or find an audio shop to do it?

Not a good idea..............The wiring in this grommet is a rats nest (loose bunched up wiring) consisting of fine wires; which can be easly cut. ......If you are to pursue this route, use extreme caution.

 

[JEEP4U]

Sorry, don’t mean to hiJack this thread, but was wondering where you ended up mounting the manager30?

In the rear cubby.........similar to the American Adventure Labs mount

 

[slim_pickens]

Not a good idea..............The wiring in this grommet is a rats nest (loose bunched up wiring) consisting of fine wires; which can be easly cut. ......If you are to pursue this route, use extreme caution.

Just to understand along with your earlier post, why is this riskier than your suggestion to cut the nipple? Aren’t you dealing with the same grommet in both approaches or am I wrong?

Most posts I’ve seen on this passenger side scenario talk about doing this from the bottom behind the fender liner. Maybe this top-down approach you suggest is easier even though you take out more stuff? Decision, decisions.

 

[JEEP4U]

I went a little further and unbolted the harness seal and pulled it away from the firewall. This allowed me access to the back of the seal, thereby insuring I would not accidently cut any wiring.

No kidding....once you pull this seal off, you will be scratching your head.....The wiring mess inside is embarrassing.

NOTE: I have a manual 6 speed.......driver side has a clutch master cylinder in place.

 

[nU7OuxIx]

Most posts I’ve seen on this passenger side scenario talk about doing this from the bottom behind the fender liner. Maybe this top-down approach you suggest is easier even though you take out more stuff? Decision, decisions.

Try to peek through the fender liner and see if you can see the wiring loom. I tried and couldn't see it after a few minutes and was like nope, going the other route.

Maybe if you take the fender liner totally off you can probably access it easier. But for me, it seemed like a lot of work and the risk of breaking or nicking something was higher.

 

[slim_pickens]

Try to peek through the fender liner and see if you can see the wiring loom. I tried and couldn't see it after a few minutes and was like nope, going the other route.

Maybe if you take the fender liner totally off you can probably access it easier. But for me, it seemed like a lot of work and the risk of breaking or nicking something was higher.

I am leaning probably 80% toward your conclusion here. For my current project, I don't have a hard requirement to run my power cable along the passenger side, so I'm not sure I want to take the masochistic route and make life harder here when the driver's side firewall pass-through is super simple by comparison.

On this topic, any advice on how to make the driver's side pass-through as robust as possible? Should I put a rubber diaphragm or boot in the blank plastic cap and run the cable through this, or just run the cable through the plastic cap along with some RTV?

 

[mikej]

For what it’s worth, you can pull the cable through the firewall on the driver’s side, then route it along the back of the footwell to the passenger side really easily. Then you can run to the back down the passenger side.

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