Unused firewall hole for power wire

I got a 2006 Tacoma v6. I'm currently installing an amp to power my front and rear door speakers.

Is there an unused hole in the firewall where I can fit a 4AWG wire through?

Also, does anybody know how to remove the trim panel on the bottom where the seat belt is bolted down to? I have to run the speaker wires through the rubber grommet and into the rear door.

 

On the passenger's side, there's a manufacturing process hole you can use. Details in this post I made about using mine.

 

If you’re careful, you can use the hole on the driver side were all your fuse box why is go in there’s plenty of room

 

Nice! Thanks for the pics. It definitely helps!

 

For the speakers, there are two terminals:
The positive side, which is the big size terminal
and the negative side, which is the small size terminal

I always buy a terminal connector kit such as this one:

Ginsco 540pcs Mixed Assorted Lug Kit Insulated Electrical Wire Connector Terminal Spade Ring Set

https://www.amazon.com/gp/product/B01C2BJIKC?ie=UTF8

It doesn't come with the small size terminals. Does anybody know where I can get the correct size for the negative terminal by tomorrow?

Also, the wire size i'm using is 14 awg

 

I'm guessing you mean where your door comes against? If so, gently pry on it with a small screwdriver or ideally a plastic pry tool. It just presses on and pries off.

 

yep, I tried it awhile ago. I had to put some leverage into it while I was pulling it. Thanks

 

That will do the trick, takes a bit of persuasion but it's just pressed on with those plastic pins on the other side.

 

There is a nipple in the grommet that seals the main harness passthrough into the cab (drivers side by the master cylinder).
Cut that nipple off and you can put pass wires through it. 4 awg wire might be a very tight fit but I was able to cram the connector for my PDU keypad through it.

 

I saw that part on the rubber grommet. I kept on pulling on it thinking that it was supposed to come off haha.

But yes, thanks for the advice! I will keep that in mind if I choose to run a sub

 

There's also a twin of this plug on the drivers side behind the top of the brake booster. I was able to easily pull it out and used small jewelers screw drivers of different thicknesses to gradually bore a hole through the center of it for the outside mirror temp display sensor harness. I was nervous about pushing through or disturbing the main harness bundle or cutting a hole in the rubber gasket around it. Nicking a wire or opening a place for water to trickle in unseen behind the carpeting isn't worth the risk for me.

It took patience and a little time, but once a little bit of the wires makes it through, it's easy to pull through the remainder and replace the plug. On the interior side, the hole for the plug is just above the carpet next the the e-brake linkage.