Amp rack dimensions and firewall hole?

So I'm at the point in my build where I need to route my 4ga power wire through the firewall. I'd like to run it down the driver side (same side as battery) for a cleaner look. Is there a factory hole or do I need to drill one? Also I plan on making an amp rack for the cubby behind the rear driver side seat. Just a simple wedge for a small Fosgate amp and two Kicker crossovers. This will conceal most the wires and look clean. Gonna use some finished plywood that I have on hand and cover it with black carpet/felt. I have the JBL Premium (not so much) system so the passenger side is already consumed with the JBL panel.

 

No need to drill!
There is a factory hole with a grommet that is easy to get to.



you'll need to cut an X in the carpet in the footwell with a box cutter or similar. You can see the screw poking through where the hole is, to the right and up from the main wire bundle


Be sure to seal the hole up with some strip caulk or similar product that stays pliable over time. Don't want water leaking in!

 

As always, thank you so much for your help Destin! Perhaps it's just the picture, but that hole doesn't look large enough for a 4ga power wire. At least needs to be 1/2"

 

I've got 4awg running though there with a bit of room to spare.

What you see in that first pic is actually not the hole. It's the head of the screw you see in the 2nd pic.

 

Awesome!

 

Could 0 gauge fit through it? If not, could I bore it out to work? Or should I just run the 0 Gauge through the rubber grommet just to the right?

 

I ran a zero gauge down the passenger side of the truck frame and drilled into the storage bin under the rear seat to bring in the wire & do a distribution block.

 

If you still your own hole like OP needed to do, you can fit whatever size you need. I have a TRD off-road model that has a different layout so I had that handy pre-existing hole. I think 4awg was about as big as would fit. So I would just drill your own hole in the exposed metal just above the factory wiring grommet

 

Fwiw, there are a good amount of rubber grommets on the floorboard of the truck if you decide to run under

 

NEVER run power wire under a vehicle. There are far too many places to go through the firewall and stay inside the vehicle. Running heavy gauge power wire under the vehicle is just asking for something bad to happen.

 

Never is a strong word. I'd agree, there are better places but a well routed cable under the cab can be just fine.

 

If its a fused & routed properly it shouldn’t matter what size the wire is. You just can’t expect that most installers would run the wire under the car correctly...

 

I was leaning towards going under the bed and up through the rear vents or simply drilling a hole at the rear. That way I don't have to worry about the thick wire and carpet and panels. I'd route it away from heat, and zip tie it route it to safety.

Also, there are round plastic grommet looking things at the rear corner of the floor. Could I drill through those? What are they? Someone in another thread mentioned going through the rear vent. Is this even possible? I live in cold climate, would that create any issues?


If I did go through the firewall, would the blank spot just to the upper-left of the factory grommet be a safe place to drill into?

Otherwise, I was thinking of going through the factory grommet in the lower left crease in the factory grommet. I tried to get a good picture angle of it. Would 0 gauge wire go through that crease? Do I simply cut an x? Then coat hanger fish it through? Sorry for all the questions. I think I am regretting my 0 Gauge decision and should have gone with a 4 gauge. Lastly what about the lower-left blank spot? I have an '18 ORDC AT.

 

I believe those plastic grommets cover the bolts that hold the body onto the frame. You can't run the wire in through the rear vent, but you can drill into the storage bin under the rear seat. I'll try to take a picture of I how I ran my zero gauge down the passenger side of the frame & into the storage bin.

 

A picture seeing how you did it would be great. Where you drilled and how you routed it. How long was your cable? Also, where did you ground back in that area?

 

Do you have a 2nd gen double cab?

I'll get some pics of everything. You need to protect the wire under the truck & fuse it at the battery. I have wire loom over the wire, then gorilla sleeve over the loom & then for a few feet of the wire I have a fiberglass/aluminum heat shield to pass by the exhaust following the OEM wires.

 

2018 Double Cab Off Road. Would just the heat shield at the exhaust be sufficient?

 

I think you should have something to prevent abrasion as well. The only reason I added the heat shield on the wire was b/c the factory wire I followed under the truck had a heat shield.

 

I didn't poke through, but I assumed these black grommets could lead me right below... I'm considering doing that for my power wire that will come up under the drivers seat.

 

Gotchya. I'll do a plastic loom, but interested to see how you routed, drilled and also grounded.