iSimple ISFD531

Dual Auxiliary Audio Input Interface with Complete Vehicle Harness for Select 2005-2008 Ford Vehicles

Available. Ships at Later Date

List price $139.95

You Save: $64.96 (46.42%)

Thanks , You Pay:


with warranty

+ FREE Shipping in US 48

Add an Extended Warranty

SquareTrade Product Warranty
Fast, Free Shipping

Within the US 48

60-Day Money-Back

Hassle Free Returns

365-Day Coverage

Warranty assistance for a year

Get FAST answers from customers ASK a Question See questions answers

Product Features:

  • Integrates two auxiliary audio sources directly to the factory radio for the best sound quality
  • Plug and play installation maintains factory wiring integrity
  • Two separate inputs, RCA and 3.5mm minijack, for use with multiple audio sources
  • Retains factory-installed satellite radio, if vehicle is Satellite radio ready
  • Compatible with select Ford vehicles
  • 1-year Manufacturer's warranty

Compatibility List:

  • Ford:
    • 2007 - 2009 Sport Trac
    • 2006 - 2007 Freestyle
    • 2006 - 2007 Five Hundred
    • 2007 - 2009 Edge
    • 2005 - 2009 Fusion
    • 2005 - 2008 F-150
    • 2008 - 2009 Escape
    • 2007 - 2009 Mustang
    • 2006 - 2009 Explorer
    • 2006 - 2009 Focus

Product History:

iSimple isfd531 thumbnail
(newest, current model)
PAC aPAC-FRD24 thumbnail
(previous model, replaced by iSimple ISFD531)

General Features

Type of Factory Radio Improvement Harness
This denotes whether the factory radio improvement module is an add-on tuner for an existing receiver, an FM stereo modulator, a plug-n-play installation harness, or if it is a portable module by itself.
Provides a Charge
This means that the cable will provide a charge to the iPod or iPhone while it is connected. On some cables that provide a charge, a power and ground connection will be required.
Factory Radio Improvement Features
This explains what exactly the unit integrates into your factory stereo. Some kits integrate many different features into your factory radio, while others add only one or two features to your existing factory stereo.
Provides Auxiliary Input
Number of Device Connections
This feature tells you how many devices you can connect to the unit at the same time. For example, some units allow you to connect an auxiliary input and an iPod/iPhone connection at the same time!
Compatible Vehicle Make and Model
The model of vehicle that this vehicle specific product is designed for. Please keep in mind that engine variations can affect the compatibility of the products.
Ford Edge
Ford Escape
Ford Explorer
Ford F-150
Ford Five Hundred
Ford Focus
Ford Freestyle
Ford Fusion
Ford Mustang
Ford Sport Trac

Warranty and Return Policy

Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider

Summary of Customer Ratings & Reviews

Rating Distribution

5 Star
4 Star
3 Star
2 Star
1 Star

Average Attribution Rating


Phoenix, AZ

iSimple ISFD531 is iAwesome OMG1337!

October 15, 2012

I purchased this product to be able to stream music from my smartphone to my stock stereo. The stock deck in my 2007 Ford Five Hundred didn't have an auxiliary 3.5" audio jack like most modern cars; although, it did have an Aux button on the radio, there was no way to utilize it. After some extensive research I found that my stock deck has the ability to accept a CD changer, Satellite radio system, or an after market device to act as the auxiliary port using an unused port on the back of the stereo. The iSimple ISFD351 simply connects to the stock radio's auxiliary port using a provided wiring harness adapter. The stock harness unplugs from the radio and plugs into the iSimple device, you then plug the iSimple device into the back of your stereo. That's all there really is to it. You then connect one of the two provided cables into the device to give you either a 3.5" input jack or you can use the component cable for L/R audio. There's also a USB port;however, the instructions weren't very clear on it's use or compatibility so I left it alone. Once it was all connected I powered on the car and pressed the aux button on my stereo, this cycles through the aux inputs that are useable. They show up as SAT1 through SAT 3 for each of the three ports on the iSimple device.(two serial to RCA or 3.5" and one USB)I selected SAT1, plugged my phone into the 3.5" cable I ran up and through my center console and had sweet sweet music playing through my stock stereo! No need for an expensive $100+ stereo and complicated installation. Cheap and does the job I asked it to.

Don't expect this to improve the sound of your system, give you earth shattering bass or anything like that. It's simply an interface. It does it's job reliably and with NONE of the static or irritation that FM transmitters are plagued with. I would buy another one of these in a heart beat. I will warn you though, this device is potentially a gateway device akin to a gateway drug... you will soon find your stock system inadequate and will want better sound. If you want to find a way to adapt a subwoofer to your stock stereo, don't do it. You can get adapters that pull signal from your stock stereo but you can only pull from either the front or rear channels at a time so you end up missing the bass tones from half the channels and it's just not a good solution. Save your time and money and buy a new deck at that point. Until then, snag one of these bad boys and enjoy some internet tunes on your stock deck.

Look/Design has 4 stars because A. Its a black box in my center console so I really don't give a hoot about the looks; however, design wise the included harness adapter is awesome and made the installation dead on easy.
Features has 4 stars only because the manual(if you could call the couple folded pieces of paper a manual) made no mention of the use or functionality, let alone compatibility of the devices included usb port. Is it for programming the iSimple ISFD531 from the factory? Is it an apple device port to allow me to control an iPod from my deck? Is it how I'll interface with the Hive mind through my car in the great robot uprising of 2050?! I don't know! Some info on that port would've been great as an internet search didn't provide any more useful information. I also got lazy and stopped caring after a couple of weeks. So there's that.

15 of 19 found this helpful

Was this review helpful to you?



Works great.

June 2, 2016

Installed this product quite easily in my vehicle in less than 30 minutes. Makes the auxiliary button useful in my Ford Freestyle instead just a button that says auxiliary.

0 of 0 found this helpful

Was this review helpful to you?

Accessory Tools and Products

Accessories added

Five Piece Installer's Panel Removal Tool Kit

Helps with removing dash and trim panels during car stereo installation.

Your Price $11.99

Scosche TK12 Car Stereo Installation Kit

Includes panel removal tool, wire cutter/stripper, test light, RCA cable runner, screwdriver, and more!

Your Price $14.99

Browse 4 questions and 4 answers
Hide answersShow all answers | Sort by
Why did you choose this?
Sonic Electronix Store
my kid wanted it for Christmas and the review was great
jeff h on Dec 9, 2014
is this good for 2007 mustang ? or the other one for shaker 1000 bass box and amp ?
A shopper on Jun 11, 2016
Best Answer: The model I purchased was for a 2007 Ford Freestyle but I believe it could also be used in a Ford 599. Not sure about the mustang but the information should be available on the box. I don't have mine anymore. It works great in my Freestyle and only took about 20 minutes to install.
Reply · Report · Len Paddick c/o D. H on Jun 13, 2016
· Add Answer · I Have This Question Too (0)
is this work on my ford freestyle se 2006, it just plugin on harness or need more work on it?
Khalid M on Apr 25, 2015
Best Answer: It's pretty much plug and play but there were (IIRC) 2 wires that you need to splice directly on the car's wires. Takes just a few minutes.
Reply · Report · Patrick D on Jun 23, 2015
· Add Answer · I Have This Question Too (0)
Do I need a stand alone
power supply for the isfd 531?
A shopper on Jan 21, 2015
Best Answer: Hello,

No, it routes power from the vehicle's harness.
Reply · Report · Customer SStaff on Jan 21, 2015
· Add Answer · I Have This Question Too (0)

Product Summary


Model Number






Internal SKU


Internal Product ID


Sonic Electronix Wiring Guide

Wiring Diagram Legend

Warning: The image depicted shows the resistance change when wiring multiple subwoofer terminals. Please refer to your subwoofer's owner's manual for the proper wiring of its terminals. Sonic Electronix, Inc. is not responsible for damage caused to your audio system or vehicle due to improper installation. Please call tech support at 1-877-289-7664 if you require additional assistance.

Product Name: iSimple ISFD531

Item Added to Cart

iSimple ISFD531

Dual Auxiliary Audio Input Interface with Complete Vehicle Harness for Select 2005-2008 Ford Vehicles


Keep Shopping

Get Added Peace of Mind with SquareTrade

Why SquareTrade?

  • The #1-Rated Protection Plan
  • 5-Day Service Guarantee & Free Shipping
  • Protection from Normal, Everyday Use
You have added a warranty
Add Warranty
3 years of protection

Five Piece Installer's Panel Removal Tool Kit

Helps with removing dash and trim panels during car stereo installation.



Don't see the accessory you're looking for?
View all available accessories for the iSimple ISFD531.