power through firewall 2012 altima

Hey everyone, I am working on an amp installation for a 2012 Nissan Altima. Having a very hard time getting my power cable through the firewall. I normally feed a piece of solid wire through the factory grommet and tape my power cable to the end to feed it through the rubber boot around the factory wires. On this vehicle, the factory grommet is covered by the strut mount under the hood, and by the fuse box in the cabin. Has anyone installed an amp in one of these cars? How did you do it? Thanks everyone!

are you opposed to drilling a new hole in a different spot? its usually the best idea even though it might not seem that way trying to poke through a factory grommet with a wire bundle already going through it has its own set of risks like damaging the factory wire and risking a short.

i prefer to drill using a step bit, unibit, etc. find a spot on the firewall that you think might be good on both sides and then locate any "landmarks" that pass through the firewall and use those landmarks to find an open spot that is clear on both sides. landmarks can include other wire harnesses, linkage cables, studs and bolts that pass through for mounting parts, and ive even used unique bends in the sheet metal to orient myself on both sides of the firewall. the reason i prefer to use a step bit is because i can drill through with the first step and check to see if the hole came through where i though before the bit goes through too far into something i dont want it to. then if you can find the small hole and it is in a safe place then you continue drilling the hole until its the size you want.

you will want to use a new plastic or rubber grommet so the sharp metal doesnt cut into your new wire. your amp kit might even come with one.

another way would be to take more of the car apart until you can get to the grommet you want to poke through, this is sometimes more work than its worth but if you definitely dont want to drill then its the only way.

For heavy cabling maybe a bulkhead connector, eg:



That's from speedwaymotors.com but there are variants.

that thing takes a huge hole to pass through and you might as well just run 0/1 gauge straight through the firewall.