best place to run 4 gauge through the firewall?

[Chrome_Rush]

I'm going to be upgrading the stereo in the next few days, haven't decided If I'm going to run a 4 channel amp or not, if I do I will run zero gauge wire to the back, but most likely I will just be running an amp for a sub and using 4 gauge. Is there a known good spot to run either 4 or zero gauge wire or is this a vehicle you just have to drill a hole in the firewall on? Usually there is at least one easy spot to run the wire on most vehicles. I hate drilling and risking drilling into something. It's a 5 speed 2wd 4 door. Is there maybe a hole where a shift cable goes through for an automatic I might have open?

 

[5spdman]

For mine (also used 4awg), drilled a hole at the passenger side firewall, towards the floor IIRC...from there, the cable runs under the carpet to a power block under the center console, which then has wires running to my amp, relays for lights, emergency lighting, CB, etc. also grabbed a firewall bushing to seal everything up.

 

[Chrome_Rush]

Seems to me the passenger side would be more difficult with all the crap in the way. I guess I will just look and see what u have to work with. I'm hoping there is a hole for an automatic equipped explorer for the shift cable to pass through that I could use.

 

[5spdman]

It was actually quite easy...the way I did it was a little more complicated, running as many wires as I did, and running ALL power through a battery switch on my transmission tunnel first, but I had taken the interior out to run all of the wiring, so it was easy, but even without removing interior, the process should be simple....I'll grab some pics for ya tomorrow...

Far as the hole for a shift cable goes, can't answer that...

 

[Chrome_Rush]

Some pics would be helpful. I actually am pulling the seats. The driver seat was in bad shape and I managed to find a perfect matching seat from a low mileage one. I steam cleaned it today but I want to do the other seats and carpet. I usually pull the seats when I get a car with some age and clean it all really well. With the seats in you just can't clean them or the carpet that well. While they are out I'm going to run the wiring.

 

[cloaked_chaos]

I ran my wire through the passenger side foot well, but it is only 8 gauge. For a larger gauge wire I would drill a hole next to that one and put a grommet in it.

 

[Wolfie_85]

There is a grommet above the brake pedal. Slice it to allow the wire through, then push it back in. Should work.

 

[Chrome_Rush]

Thanks guys I will look into these areas. I'm hoping to get it in in the garage in the next few days.

 

[5spdman]

Really simple, really quick...as you can kinda see in the first picture, the wire actually passes over the transmission between the body and heat shields.
Running a wire just for an amp wouldn't have yours running low as pictured...my set up is that way since I have 2awg running to the battery kill switch from the battery, and then 4awg and 8awg running from the switch to the power block for the amp, etc under my center console, and to the fuse/relay block under the hood and starter...only power that isn't killed with the switch is the radio constant (memory.)

 

[Chrome_Rush]

Is your battery on the driverside? I kind of see how you did it. But why did it need to go over the transmission like that. Unless the battery on my 91 is on the opposite side. Passenger side battery going through passenger side firewall it shouldn't need to go over the Trans like that. I must be missing something. I have 2 zero gauge kits and a new 4 ggauge.im just not sure I want to go through the hassle of running a 4 channel amp. With the bass cut out the mains get reasonably loud with the pioneer replacement speakers before distorting. It's not ear shattering loud but I don't really need that these days. I have 3 4 channel amps 2 2 channel amps and 2 mono sub as collecting dust from previous installs as well as a few sets of subs. Debating using 2 12" pioneer champion series subs that are in a built to spec slot port box on a 70k rms amp or a single sundown sd-2 12 in a spec built sealed box I also have with the same amp. I have all this stuff I should use some. It's just a matter of how much work I feel like doing.

 

[5spdman]

Battery is on passenger side, but the kill switch I installed is on the drivers side of the transmission tunnel...that's all you're missing.

 

[Chrome_Rush]

Ahh I wasn't clear on that. Now we're cooking with fire. So I won't need to do that. My step drill bit should make quick work of this job then. Just have to jack it up so I can get my ass under it far enough to drill the hole.

 

[5spdman]

I'd just drill it from the inside...that low on the firewall, there's nothing to hit on the engine compartment side and you'll see the wires inside the cab to avoid hitting.

 

[Chrome_Rush]

Well I got everything installed. Ran the wire through the grommet on the lower passenger side. It's just big enough to squeeze the 4 gauge through. Mounted the amp to the back of the rear seat and threw my sundown 12 in back. Started the truck and tuned the stereo.

After 15 minutes or so the sub started burping strangely even with the sub output turned off... then the under hood inline fuse blew. Turned off the sub output and replaced it. All was good, turned on the sub output to try the amp it turned on for a split second and blew the inline fuse again. Wtf

 

[5spdman]

What do you have for a head unit and amp? Other than the fuses blowing, I had the some problem before I installed my Pioneer....problem is, I couldn't figure out the problem, and I can't remember what head unit I had in before....might have had something to do with the amp itself too...

 

[Chrome_Rush]

It's a pioneer head unit I want to say it's a deh-8400hd. I bought it and put it in my GMC truck about 6 months ago. But I'm selling the truck so I figured I would take the older jvc unit out and put the new one in the explorer. Especially with it having HD radio, (which is awesome if you love in a heavily populated area. You get a ton more good stations and they all come in clear) and also bluetooth for audio streaming and a microphone you connect to the sun visor for hands free talking. It's awesome to have especially driving a stick.

That is hooked up to 4 pioneer 6x8 speakers in the doors. I did figure out the amp blew out though. If the fuse or wire wasn't of sufficient size it would have caused the fuse to blow when the volume and the for the amperage load got to high for the fuse. It piped the fuse as soon as I turned it on though. Which means the amp has an internal short. I swapped the amp for another one I had and it's up and running. This amp is much smaller then the one and rated much lower power wise. But still sounds good. The one that blew was a crunch pzi-1500. Supposed to do 750 rms at 1 ohm. But I think it's just a bit overrated. I think it's more like 600 rms power. The amp I put in is a much lower wattage clarion apa250 amp. They claim it's only 100 watts rms bridged but it's way underrated. This things rattling the rear lift gate, and even the sunroof cover lol. I think it's more like 200 rms. The sub is underrated for 600 rms, I have thrown a lot more then that at it, and this little amp has no trouble pushing it. I would like a touch more power but for now it's good.

I have 2 12" pioneer premier champion series subs that are practically new in a nice slot port box I think I'm going to sell or try to trade for another amp. I will never install it in anything. It's to freaking heavy lol.

The sundown sub weighs in around 30 pounds. I made the box out of 3/4 birch instead of 3/4 mdf and it weighs about 8 poinds I think. Together the sub and amp is under 40 pounds. With the amp mounted to the seat it only takes me a minute to disconnect the speaker wire and pull it out to haul something really big. But it's only about a 10 inches deep and is as wide as the larger section of rear seat. It's the same height as the rear shade cover. Doesn't take much room up at all. I can still use the shade and can turn the box sideways to haul almost anything. But if it does need to come out it takes less then 1 minute and it's light enough to carry anywhere. I'm very happy with how it all came out.

The interior is all steam cleaned and driver seat replaced with an exact match in new condition. Dash and door panels scrubbed. This thing is coming along nicely.

 

[Jason94sport]

There is a grommet above the brake pedal. Slice it to allow the wire through, then push it back in. Should work.

4 Explorer's, 4 cables run this way. 4GA