GATORB8

Make sure you run it in conduit if your going under the truck to protect it.

brocken

Yup, that's what the liquid tight tubing is for. It's nice and flexible unlike metal conduit but should still protect the wire nicely.
The fun part now is drilling into the frame for clips to hold the conduit. Drilling thick metal sucks!

dsm07fx4

going under the truck is in my opinion the way to go. Of course you have to protect it and keep it as tight to the truck/frame as possible but as mentioned already you don't have to worry about all the signal wires... and running it through the cab.

This is the way i'm going for sure.

statikuz

Depends on how thick of wire you're trying to run. I don't think you could use it for any more than 4 ga. But that's enough for all but the most power hungry installs. I didn't have a problem fishing it through to under the dash. The carpet kinda covers up the hole but not too bad.

brocken

4 ga might have been doable. I'm running something between a 2 ga and 1/0 wire. With that inch of clearance inside it just wasn't enough to make the turn. My sub amp is up to 1k watts and the 4 channel is somewhere around 500. Not that I'll use all of that all the time but I wanted to make sure my wiring was sufficient.

That secret grommet under the passenger door seems like it was meant for running power wire. I have my caraflex run and about to fish the wire through. The only thing I have to figure out now is how to secure the conduit. I'm still dreading drilling the frame for clips.

lray801

I actually found that the rather large rubber insert that the main bundle of wires runs through has a bulbous part that sticks out on the top. If you cut that little guy open, it gives you a straight shot through that 4 gauge wire fits through quite nicely. No need to drill holes or run by the frame. Going through this will put you right under the dash on the passenger side. I highly recommend using it!!!

'09 F-150 SuperCrew

castaway

I found a gromet directly between the battery and the firewall, i think it was 8ga wire I ran through it, and it came out under the dash on th passenge side, it better than pefect for my amp power.

Tater

I had it professional installed and they into the firewall with all the rest of the wiring, you can't even see it but at the battery and the piece connected to the amps. Looks great!!

Beechernic

Im not sure if you solved this or not, but I just installed my amp wiring this weekend and it was a snap!!!

On the front fire wall, behind the GAS PEDAL, there was a manufacured hole (2" DIA) with a rubber seal over it.

1. I ran the wiring from inside the cab, out through the FireWall into the engine area. I had NO CLUE where the hole was under the hood, but it was easy when three feet of bright blue 4gauge snake dangled on the ground.
2. I ran the appropriate amount of length to the battery. I mounted everything appropriatly under the hood.
3. I used a Utility knife to put a slit in the rubber seal. Make sure it is small and tight (envision your first cherry poppin moment). I wanted to ensure I didnt lose the integrity of the seal.
4. I CAREFULLY fed the power cord (aprx 15') through the seal. No reason ripping that virgin open, and possibly get your feet wet in the future.
5. I pulled up the plastic trim along the flooring and some of the carpeting and ran the rest of the wiring to the rear of the cab.
6. Replaced the carpeting and trimming, and finished my beer.


Hope this helps. Again - the focal point of this synopsis is to explain that there is already a FireWall incision somewhere.
Think of it this way...Columbus didnt 'discover' America. There were already indians here. And those indians knew Columbus loved Hard Rock and Rap music.

castaway

I dont think this will work for two 2 gauge wires, but it worked for me!

https://www.f150forum.com/f4/amp-wiring-55461/