How do I run a 4 gauge power cable through the firewall?

1998 Tacoma

I see the two rubber grommets, one on the driver's side and one on the passenger side, which wiring harnesses run through.

Obviously I am targeting those as the channels to run this power cable through.

However I am stumped as to how I accomplish this.

For starters I can barely fit my hand(s) up behind the dash in either spot and can barely fit my hand between the brake booster (?) and the spot on the firewall in the engine bay.

Any tricks of the trade anyone can share with me?

 

I used a slightly sharpened coat hanger with the wire taped to it. Pushed it through the engine bay side of the firewall.

 

exactly

 

I ran 2 gauge through the firewall using the existing grommet on the drivers side. No need to drill anything.

Grab a large pair of scissors and poke them through the rubber grommet in an area where the wires aren't. In fact, I believe there's a small slit in it already in an area. Poke them through the grommet to make your own hole. When you get through the other side open the scissors slightly to widen the hole. Then pull them out. After that you just push the wire on through. Easy and requires no extra parts!

 

x2

 

x2 on the coat hanger, poke it thru the rubber grommet,tape the wire to it and push thru reach up under dash and feel around for the coat hanger and slowly pull it through. It might take a couple of tries if the wire pulls off the coat hanger.
Another way I've done it is I have a broken aluminum arrow shaft that I cut down to 6 in with a angle point on it. Push it through the rubber then feed your wire through the center of the arrow shaft.

 

4 gauge wire is much larger in diameter than a coat hanger or arrow shaft.

 

I'll try getting the #3 flathead screw driver through the grommet again.

Then what I might do is affix a zip tie to the cable push the zip tie through, then reach up behind the dash and just try to pull the facker through the grommet.

 

I'll try getting the #3 flathead screw driver through the grommet again.

Then what I might do is affix a zip tie to the cable push the zip tie through, then reach up behind the dash and just try to pull the facker through the grommet.

 

I have seen firewall rubber grommets that are tapered to what ever size harness or wire you are putting thru it. you cut at the size you need and it is self sealing in the engine side. also looks like a cv boot except the firewall side is flat with a lip to lock onto the sheet metal.

 

Poke through it with your largest screwdriver. Make a new hole inside the grommet, at least thats my preference. From there on its being a man and pushin hard. Sometimes you can take a smaller screwdriver, tape the shit out of the wire ONTO the screwdriver and pull it through, but 4 guage is rigid enough to just push through.

 

I was waitin for someone to pick up on that

 

/\ truth bomb right there. The zip tie trick also works for snaking wires through the door hose elbow things.

 

Has anyone other than me tried to route the power/ground wires from the engine compartment down inside the frame rail then up into the rear of the cab where most people mount their amplifiers? I know there are grommets in the floor of my doublecab behing the rear seats. I am going to be using two of the floor grommets to route my subwoofer wires from my amplifier box I mounted in the bed of my truck.

It's just an alternative way that I thought about running my wires. I even went as far as wrapping my power/ground wires with corrugated sleeving to help protect the wire and to also give it more of a factory look to my installation.

 

Nothing wrong with that IMO. I've done it before....not on taco tho. It definitely helps to have some extra insulation if you're gonna be rubbin against the frame tho.

 

Cut a peice of the grommet with an exacto knife and silicone back, I have 2 (4 gauge) wires and 6 #12 gauge wires running through mine.

 

Saw you were a first gen, not sure if the grommets are different in 2nd gens

 

and then a guy walked into a bar and said "Hi, my name is Large!, I wear three legged pants!"