Metra 70-5521 Radio Wiring Harness for Ford 03-Up Amp

Just bought a ‘04 Lincoln Town Car and didn’t know wether it had an amp/sub or not(couldn’t speak with original owner as it was purchased through a family member and the manual was missing) so I went with this harness because if I didn’t need the amp out harness no big deal, but if I did...well then I’d need it lol. The harness itself is perfect for what it is, a simple harness to prevent cutting and splicing the OEM harness, wires were clearly marked and colors matched the harness for the after market stereo. Went with the Pioneer AVH-X490BS, if you get a pioneer look into getting the parking brake bypass switch. The only problem is that there was nowhere to connect the two blue wires on the harness with the RCA plugs, so I assumed I didn’t need it and just didn’t use it. Reconnected negative terminal on battery and tested radio and it worked great so I figured I was right. I go to install the Infinity Kappa speakers in the rear deck(btw if you have a Town Car be ready to take out the entire rear seat, both bottom and rear cushions to get access to the speakers......) and guess what I see?? A sub and amp.... I was planning on getting an amp for the speakers anyways, and maybe a 8” sub just for a little bass so I’ll just wait to get them rather than hook up the factory amp/sub. If you're replacing a radio you can’t go wrong with Metra, always quality products. Been using them as long as I can remember, and between work, my personal vehicles and friends/family I’ve installed more car stereos and speakers than I can remember and never had an issue with Metra.

Worked with my radio just like it should

Even thought this is labeled for Ford, this was a perfect fit for my 2008 Hyundai Sonata. This item comes with two adapters, I did not need to use the harness with the smaller adapter, I believe this might be to connect an amp which I did not need. I was struggling to find the correct adapter for the 2008 Hyundai Sonata because searching on amazon and google were not leading me to this adapter from Metra since it is labeled for Ford. I came across a youtube video with a guy working on the Hyundai Sonata 2008 and he was using this specific cable model Metra 70-5521 on his stereo. So I decided to order it after searching it up and comparing the adapter to the car's factory adapter. It worked out great because it was a perfect fit. I youtubed enough about the basics of wiring cables together, what the different colors mean, pros and cons of wiring directly to the factory unit wiring (using no adapter). I found videos of others removing the stereo for my specific car (I didnt want to just pry it apart and damage something). Then I went the method of butt connectors to link the wires from this harness to the cables of the stereo unit. The connection quality is strong, the cables from this harness are sturdy so they link well. I used it to adapt an aftermarket radio (BOSS Audio Systems 616UAB single din) using the car's existing factory wiring and connectors. I got the single din install kit (Metra 99-7320). I also got the LeeKooLuu Backup Camera and wired it to the Reverse tail light. I installed this for my girlfriend and it passed her approval test. Everything came together perfectly.

I used this in an '06 Mustang GT. It was easy to wire up, everything was labeled nicely and wiring is good quality. If you have an amp, there are a couple extra items you may need. First is a 12v to 5v voltage converter, this just gets tied into the amp out (blue/white), otherwise you may get popping sounds with On/Off. The second in my case, I needed to add a line out converter from the RCA. This allows me to adjust the gain. Initially I wired this up without it and the sound was terrible, way too much volume sound coming from the amped speakers. I emailed their tech support a few times, they were helpful but ultimately the manufacturer of the head unit I bought recommended the solution. Otherwise it works as intended.

I used this harness to upgrade to an aftermarket head unit on my 2005 f250 6.0. Worked flawlessly. My new headunit did not come with steering wheel control functions and says you have to buy the harness for it seperately. You do not. Its a very simple process to retain your functions that i learned about way later. Your upgraded headunit will have a harness included. On that harness it will have a wire labeled "Steering wheel key (+)" and it is orange with a black stripe (atleast on mine) Your stock truck harness will have a blue/red stripe wire on Pin #18 that you must tap into. You dont have to cut it, you can simply military splice it, or use a T-tap to connect the SWK wire on your aftermarket radio harness to connect to your factory harness. Once you connect this SWC(+) wire onto the blue/red wire.. you will be able to setup your functions on your radio. Thats it. One wire. No need to buy the access module or the maestro kit thats around 100 if you have a powerstroke. Hope this helps someone.

Metra 70-5521 Crutchfield claims this kit does not exist or work on my 07 Mustang with the Shaker 500, and insisted I purchase an expensive PAC kit that requires soldering a diode. With the 70-5521, there are 2 harnesses. The large one is for the main radio harness, the smaller one is for the Shaker 500 subwoofers. You will need a LM7805 or equivalent voltage regulator to convert a 10-15 V signal into a 5V signal. The LM7805CT voltage regulator was needed because the Ford factory Shaker 500 amplifiers require a 5V turn-on signal, while aftermarket receivers use 12V turn-on signals for the amps. This results in a pop or overload of the amp turn-on. The LM7805CT seems to do the trick, and I was told by other Mustang owners not to worry about heatsinks or cooling the regulator because the current/power dissipation isn't that great. I also observed that it was definitely possible to tap into the light/illumination leads for either the message center harness or the HVAC harness to enable the dimming feature on the CX501, but I opted not to touch the factory wiring. The main factory harness does NOT have a power antenna (solid blue), amp turn-on (blue/white) or phone mute (brown) so those must be sealed/wrapped off on the big Metra harness. The smaller Metra harness that goes to the Shaker 500 will have a pair of amp turn-on leads (blue/white) that attach to the OUTPUT side of the LM7805. The INPUT side of the LM7805 goes to the amp turn-on lead coming from the receiver harness. The RCA inputs for the Shaker 500 subs go to the appropriate RCA jacks on the back of the receiver. I soldered all of the ground leads together which goes back to the receiver harness ground lead. I used solder and heatshrink wrapping and can confirm that this wiring kit will work on a 05-09 Mustang (or at least the 2007). Overall: 5/5 stars, very inexpensive, not hard to use, just remember to buy a 5V regulator from Radio Shack - I opted to buy my Fairchild LM7805CT from Digi Key so that I knew I was getting a quality regulator.

Great product. I've had my new deck installed successfully with this product since Jan 2016, but my steering wheel controls did not work. Be aware that this harness doesn't have pins/wires in every hole. For my Ford, you need Pin 18 to install the ASCW-1 unit into. I ended up not using my ASWC-1 from Jan-May, and I finally decided to get it going again. Since I did not want to harm any factory wires in any way (Metra suggested cutting insulation back on the factory wire and taping the SWC wire to it), I opted to buy a second harness, and remove a pin and wire from it to install into my existing harness. For $5 more, it's not a bad option but Metra really should include an additional wire or two with it for folks with Steering Wheel Controls. There's a Youtube video about it, but it's a lot easier than it looks. You remove the red piece inside the harness, push the tan plastic down under the pin, and that frees it. Then you take the your actual harness, locate the needed pin slot (18 in my case, 20 was marked so it was easy to find) and just push it right in until it clicks. I really wish I would I would have read about this before starting my install. This method will give you a wire to solder or connect your steering wheel control module to. For Ford, it's the green/white wire. I'm the sorta person who will spend way more time and money to do a job the right way, so that's why I bought two. I really hope this helps! Enjoy!

I rated this one star, and Not because there is a problem with the connector. The problem is with the vehicles that it supposedly fits. What I learned is you can't rely on AMAZON's recommendations, or METRA's either for that matter. Amazon recommends this Metra 70-5521 harness for the 2004 Mustang. Let me share with you, the joy of spending hours in prep work, soldering the harnesses together, heat shrinking the connections, removing the cars interior and stereo, to then find out the recommended harness doesn't fit. (But the Metra 70-1771 harness that Amazon says does NOT fit, actually DOES fit...at least mine) By now you have your car ripped apart, your front yard looks like a junk yard and now learn you have to drive around town to find the correct harness. The added insult to injury is not only being bent over and paying 3X the price for the correct harness locally, but also having to pay return postage for being misled. Apparently there were several models of stereos installed in the 2004 Mustang, and there are at least three harnesses that 'may' fit. Just because the faceplate says MACH, don't assume that you have a MACH stereo system. Unfortunately, unless you are a car stereo expert, the only fool proof way to tell is to go through the PITA procedure of pulling the head unit and looking at the connector you will need prior to ordering. The METRA website is also useless. As I learned the hard way, you still may not get it right. One harness is completely different from the other two, which happen to share the same connector, but one has more wires than the other. Other clues may be, does your head unit play 1 CD or 6 CD's? Does it have a factory amplified subwoofer that fills up your trunk? I thought that I did my 'due diligence' prior to ordering, but I was wrong. Good Luck in doing yours..

El arnes quedó a la perfección, muchas gracias solo que al querer conectar el arnes chico mi camioneta ya no trae el conector macho que es para el subwoofer de fabrica que trae la camioneta la cual es una explorer eddie bauwer 2005.

This just arrived after waiting patiently for its arrival from the USA. Unfortunately this does not fit the Ford Explorer 05 as stated. Good quality item, but clearly a waste of time and money as seller is USA based, this isn't worth a return!

I used this to install an aftermarket stereo in our 2010 F150 with no Sync. I searched many places and couldn't locate the correct harness for my truck. I could tell physically this would fit so I used it, however I know it's not intended for my truck. That said all speaker connections were perfect, yellow memory and ground matched, only the illumination wire didn't match so I moved that pin. Great quality and worked well.

TODOS los productos Metra que he comprado a traves de los años han sido extremadamente precisos, me ayudan a presentar un trabajo super profesional, mejoran enormemente el "look" de mis automoviles, y me facilitan la instalacion de los nuevos estereos. Siempre que pienso en un estereo nuevo para mi auto, lo primero es encontrar el producto Metra adecuado al vehiculo, y siempre lo hay.

Fits Perfectly and works as it should, good plug ... Fits Perfectly and works as it should, good plug ... Fits Perfectly and works as it should, good plug ...