GMC Truck Forum banner

Running large gauge wire through firewall to cab in a 2015 GMC Sierra

147 Views 3 Replies 3 Participants Last post by  PhilSchuyler
I need to run a couple of large wires from my battery in the engine bay to the space under the back seat in my 2015 Sierra SLT for some amateur radio equipment. I need at least 100 amps. What’s the best way to get through the firewall? Do I need to drill a new hole or can I fit a couple of #2 awg wires through the one of the existing grommets somewhere? And if so, where’s the best place to drill it?
1 - 4 of 4 Posts

· Registered
Joined
·
969 Posts
Does it need to go to the dash area or are you running to the back of the cab?

If you are going to the back of the cab (I am assuming that is where the amp is) I would run the wire along the frame rail and come up through the floorboard with some grommets. I always find it a pain in the ass to get the wires from the dash to the back without bulging up the carpet or door sill trim.

To answer the question though you will probably have to drill somewhere anyway, the grommets under the dash aren't big enough for 2-2ga wires.
 

· Registered
Joined
·
1 Posts
I ran some 00 gauge wire through the vent flaps on the back of the cab on my old MegaCab and on a 2021 Canyon AT4 I had for about a year. Only thing I had to do besides pull all the plastic paneling back was snip a little piece of plastic on the flap housing. Ran a 2000 watt power inverter with zero issues. Depending on how tight the spacing is with your bed, you might need a fishing wire, but if you feed it from the cab out the panel, you might be able to avoid it


Sent from my iPad using Tapatalk
 

· Registered
Joined
·
2 Posts
Discussion Starter · #4 ·
Does it need to go to the dash area or are you running to the back of the cab?

If you are going to the back of the cab (I am assuming that is where the amp is) I would run the wire along the frame rail and come up through the floorboard with some grommets. I always find it a pain in the ass to get the wires from the dash to the back without bulging up the carpet or door sill trim.

To answer the question though you will probably have to drill somewhere anyway, the grommets under the dash aren't big enough for 2-2ga wires.
That’s what I thought. I think I’ll leave it to a professional. I have an appointment in a few weeks with audio installer. But thanks for getting back to me.
 
1 - 4 of 4 Posts
Top