Rockford Fosgate RFK4

4-gauge amplifier power wiring kit

Item #: 575RFK4

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14 Reviews

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This wiring kit does not include speaker wire or patch cables. You will need to purchase those separately, in order to complete your amplifier installation.

Your amp needs big power wires in order to deliver top performance to your sound system. Rockford Fosgate's RFK4 amplifier power wiring kit supplies everything you'll need to send power to amplifiers with fuse ratings of up to 100 amperes. Rockford Fosgate makes the 4-gauge cable from 100% pure crystal-oxygen free copper wire so you can count on maximum signal transfer.

Product Highlights:

  • amplifier wiring kit
  • cables meet or exceed the American Wire Gauge specifications and requirements
  • 17 feet of 4-gauge power cable
  • 3 feet of 4-gauge ground cable
  • 20 feet of 18-gauge turn-on lead wire
  • AFS/MAXI fuse holder and 100-amp MAXI fuse
  • assortment of wire termination hardware and cable ties
  • warranty: 1 year
  • Our 60-day money-back guarantee

Rockford Fosgate RFK4 Reviews

Average Customer Review:

14 reviews
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Quality kit

Written By Anonymous, Honolulu, HI on Tuesday, June 30, 2015

Crutchfield Customer Review (What's this?)

Great quality amp wiring kit, wires are thick and flexible with nice quality sheathing. An old 8ga Efx kit does not compare in terms of quality. Installed in a ford ranger extended cab with plenty of wire to spare.

Pros: Great quality

Cons: Doesn't come with a patch cable


Written By rabuckg, Oklahoma on Saturday, June 06, 2015

Crutchfield Customer Review (What's this?)

Simple, clean and easy product to install.

Pros: Nice gauge size that can handle about anything you throw at it. I only have an 800 watt amp, but if I ever upgrade to more power, it is ready for it!

Cons: None

Great kit

Written By Jeff S, Alabama on Friday, April 03, 2015

Crutchfield Customer Review (What's this?)

This is a great kit and the wire is of great quality. We installed this in a Ford F250 crews cab truck and the 17' power cable was not long enough, but we had additional high quality wire from a previous install. Recommend you measure closely to make sure you will have enough wire. The only negative was that the fuze holder location was already fixed in place and did not allow us to place fuse where we wanted without wasting wire.

Pros: Quality wire, everything included in kit.

Cons: fuse location was already determined.

Just what you need.

Written By Wrangler, Maryland on Saturday, January 17, 2015

Crutchfield Customer Review (What's this?)

High quality product. Cable is 100% copper and there is plenty of it.

Pros: quality

Cons: none

high quality

Written By stan, michigan on Thursday, August 28, 2014

Crutchfield Customer Review (What's this?)

this is a high quality amp installation kit. just what you would expect from rockford fosgate.

Pros: high quality, all the wires are more than long enough

Rockford Fosgate RFK4

Written By Dillon, San Antonio on Thursday, August 14, 2014

Crutchfield Customer Review (What's this?)

Just what you need to add an amp

Rockford Fosgate RFK4

Written By Ed, LA on Thursday, July 31, 2014

Crutchfield Customer Review (What's this?)

This is a nice kit and the wire is exceptional. Everything needed for installation is in the kit. Comes with a 100 amp fuse so if you need a smaller size you will have to purchase one. And, if you need a larger size better check into a different option. Larger size fuses are not compatible with this fuse holder. The 17' power cable may come as a challenge if you have a crew cab truck. It worked in mine with no wire to spare. I would recommend making a closely accurate measurement from where you will mount the power amp and the route you will be taking before purchasing.

Pros: Nice kit. Exceptional quality. Has all the necessities without paying extra for unnecessary frills.

Cons: Make sure your amp doesn't need a larger than 100 amp fuse. Wire length may be a challenge if you don't do some pre-measurements. Especially on crew cab trucks.

Great Wiring Kit

Written By BlameTheBird, Destin, Florida on Friday, April 25, 2014

Crutchfield Customer Review (What's this?)

This cable is very flexible, which made it easy to run through my truck. The plastic firewall grommet that comes with this takes a 5/8" hole and then the cable fits loosely through it. I went and got a 1/2" rubber grommet, and then dressed out the opening so that the cable would just slide though the hole. I attached the power cable straight to the tightening bolt on the battery terminal without having to modify the attached connector and was able to attach the 2' long negative cable to a seat mounting bolt once I filed the hole in the attached connector out a little. Overall, a nice setup, other than the fact that it came with a 100 amp fuse and my amp recommended an 80 amp fuse. A little pricy, but with the 50% off deal from Crutchfield when I bought this at the same time as I bought a power amp made it very worth the price.

Pros: 17' long positive cable was plenty long to wire my pickup truck. Supple cabling is easy to run.

Cons: Plastic grommet seems a bit lacking.

Worthy amplifier wire kit.

Written By Amplifier wire kit., Chesapeake, VA on Tuesday, March 18, 2014

Crutchfield Customer Review (What's this?)

Good value for your buck.

Pros: Won't dent your wallet

Cons: None


Written By Mike K., Plainfield, Illinois on Saturday, November 23, 2013

Crutchfield Customer Review (What's this?)

Good quality wires with enough to get the job done right!

Pros: Fine quality wires and not cheapy stuff!

Cons: None

Rockford Fosgate RFK4

Written By GeorgeD, Atlanta, GA on Tuesday, April 09, 2013

Crutchfield Customer Review (What's this?)

Good quality wires. some good hook ups plus a great fuse holder

Pros: N/a

Cons: N/a

Limited connection options

Written By Jjkinsd, San Marcos, CA on Wednesday, May 16, 2012

Crutchfield Customer Review (What's this?)

Wire is great quality, provides power where you need it! Came with enough power and ground wire to wire a distribution block and two amps, so that's a plus!

Pros: Quality

Cons: Not enough crimp connectors for the #4 power and ground wire for one amp! In my opinion, at the price of this kit, you should be provided with more connection options as these can be hard to find around town. (I paid half price since I purchased with amp, thanks Crutchfield)

Perfect kit for sound board

Written By Keith, Marrero, LA on Saturday, February 04, 2012

Crutchfield Customer Review (What's this?)

Great package as wire and fuse was nothing like they used to put out with their amps. I ran it to a power distribution block to serve as the source power for all of my components. Everything was mounted to a piece of 1/2" MDF board so there was no need to run separate wiring for my subwoofer amp and sound processor.

Pros: Nice, complete package, 100 amp fuse was perfect as I had 2 other components running off of the souce power it provided. Easy to handle wire that also went through a spare grommet in the firewall.

Cons: It did not have a spare fuse; though you should not blow one anyway, it's still nice to have so you are not down should it blow for some reason.

Nice Kit.

Written By Kevin, Mesa, AZ. on Saturday, June 19, 2010

Crutchfield Customer Review (What's this?)

This is a nice kit and made it easy to wire in my new JL XD 600/6 amp. I was worried that the power and ground wires were a bit to short for my 2001 Chevy Silverado Z71 extended cab. However, there was plenty of wire for both the ground and power to wire in the amp under the back seat. The large gauge wire was plenty flexable to run around corners in the truck. The only downfall I can see it that I had to get a better firewall bushing to run the power wire to make sure it did not get nicked. I also replaced the included 100 amp fuse with a 60 amp fuse since JL recomended a 50 amp fuse if you run a single XD 600/6. Save your time running all over town getting wires and get this kit.

Hands-on research

What's in the box?

Download owner's manual

  • One 17' Power cable (4-gauge) in a red translucent jacket (has an in-line fuse holder and a ring terminal on the battery end)
  • 3' Ground cable (4-gauge) in a translucent gray jacket (with a ring terminal on one end)
  • 20' Turn-on lead in a blue jacket
  • 100-amp Maxi-fuse
  • Power Ring
  • Ten 4" wire ties
  • Plastic grommet
  • 2 Plastic butt connectors
  • Female quick slide connector
  • Male quick slide connector
  • Small red rubber boot
  • Large black rubber boot

Product Research


General Overview: This is a single amplifier wiring kit that includes the power and ground cables, turn-on lead, and other accessories required to install one amplifier. Speaker wire and RCA cables are sold separately.

High Strand Power/Ground Cable: The power and ground cable are 100% Pure Crystal-Oxygen Free Copper (PC-OFC) and meet or exceed AWG (American Wire Gauge) requirements.

In-line Fuse Holder: The included in-line, water-tight fuse holder attached to the power cable comes supplied with a 100-amp Maxi-style fuse (not pre-installed in fuse-holder). The fuse-holder will also accommodate an AFS-type fuse.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Looking for more? Check out the next model in this lineup.

Rockford Fosgate RFK4X

Get all the power and signal wires you need in one kit:

The Rockford Fosgate RFK4X offers these features:

  • one 20-foot twisted pair RCA patch cable
  • 30 feet of 16-gauge speaker wire