Has anyone run cable through the firewall on the passenger side?

I'm building a dual battery system in the back seat of my 23 and need to run 4 gauge wire from the battery to the passenger side of of the vehicle, where the battery will be. Have any of you run wire on that side before? What's the easiest way to do it?

 

Theres a large 3" dia. bung on either side, a nipple big enough for 4~8gauge wire is already there, snip it and snake the wire through the firewall and under the bottom trim panels. You may want to consider running one wire on either side as a single 4 gauge is all that is going to fit under those trim gutters, already some wiring in there too.
You can also run the wires down under from the engine bay, tucked alongside the inside frame and into the rear passenger area from below, theres another cap underneath the rear bench seat you can snake wires through. The latter by experience is the easiest

 

Double and triple check in and out before you drill for anything you could accidentally knick. Then drill a pilot hole check again and then use a step up bit . Use a grommet and you should be good to go.

 

I admittedly dont know much. Are the batteries in the back at least in some kind of enclosure?

 

Why not run it underneath the truck? There is a factory hole in the floorboard behind and in between where the back seats mount, this is where I ran the cables for my auxiliary battery

 

Thanks! Got any pictures? I think that's probably the best way to do it.

 

I'm building a modular dual battery system enclosed in a packout and connected to the chasis with an Anderson connector.

 

Thanks. I plan on returning the lease so I don't want to drill holes in the body.

 

That sounds like the best idea. Do you happen to have any photos?

 

That side is all CAN networks wires go through. Will be expensive if nick even one.

 

New to Tacomas but why the need for an extra battery? Isn't it going to require a new high output alternator to charge it also? Honest question.

 

It's a lithium house battery to run a fridge, camping lights, a weboost, and electric blankets. It doesn't need a bigger alternator. It charges of alternator power with a Victron DC-DC charger.

 

Damn, shit has changed in the last 20 or so years. I am still thinking of my old car audio days when we put extra batteries and high output alternators in. thanks for the info.

 

Here’s a pic from underneath. There is a black rubber plug in the hole

 

Thanks! Did you have to remove anything inside the cab?

 

I did remove the back seats and built a platform with storage underneath and a place for my auxiliary battery system but even with the seats in the hole isn’t obstructed except covered by the carpet which can be pulled away

 

Thanks! I'd love to pull the rear seats but I'm trying to keep it as stock as possible while still being really capable.