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Metra 70-7904 Receiver Wiring Harness

Connect a new car stereo in select 2001-up Mazda vehicles

Item # 120707904

This vehicle-specific wiring harness makes connections between your new car stereo and your car's electrical...

Find what Fits your vehicle

This vehicle-specific wiring harness makes connections between your new car stereo and your car's electrical...

Discontinued item
2 questions - 7 answers

Item # 120707904

Since 1974

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About the Metra 70-7904 Receiver Wiring Harness

Metra 70-7904 Receiver Wiring Harness

This vehicle-specific wiring harness makes connections between your new car stereo and your car's electrical system.

Metra 70-7904 Receiver Wiring Harness

This vehicle-specific wiring harness makes connections between your new car stereo and your car's electrical system.

First, attach the color-coded wires on your Crutchfield-supplied harness to the wires from your new stereo. If you're not using a soldering iron, we recommend that you purchase some wire connectors to secure the connections. Check out our handy article on three ways to connect the wiring harness here.

Now, once this harness is connected to your new stereo, you'll be able to plug right into your car's factory radio connector. This harness makes installing your new stereo easier, and allows you to put the factory radio back when you sell your vehicle or return it at the end of the lease. A detailed instruction sheet comes with the harness. Warranty: 60 days.

Please read this important note: This harness may not contain provisions for every wire needed to complete your installation, and it will not accommodate special navigation, video, or factory steering wheel control connections. You will need a special adapter if you want your factory steering wheel audio controls to work with your new stereo.


What's in the box:

MFR #70-7904C

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Crutchfield response

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More details on the Metra 70-7904 Receiver Wiring Harness

Stacey B.

Product Research


Crutchfield Wiring Harness: Crutchfield wiring harnesses prevent you from having to cut your vehicle's factory radio plug when replacing your factory radio with an aftermarket head unit. Simply solder or crimp the Crutchfield wiring harness to your aftermarket head unit's harness (solder & crimps not included), plug the aftermarket head unit's plug into the rear chassis of the aftermarket head unit, and plug the Crutchfield wiring harness into your vehicle's factory radio plug.

Note: Installation tools, hardware, & accessories are not included & sold separately. Please see the Accessories tab for recommendations & availability.

Wiring Notes: If the Crutchfield wiring harness is not equipped with a ground wire, you will need to ground the aftermarket head unit's ground wire to the metal chassis of your vehicle. Some vehicle's may require you to bypass the vehicle's factory amplifier (in another location from factory radio) or hardwire certain connections. If your vehicle is equipped with factory steering wheel controls, an additional adapter is required & sold separately.

Wire Code Chart:

Wire Color Function
Red +12 Volt Accessory
Yellow +12 Volt Constant
Black Ground
Blue Power Antenna
Blue/White Amp Turn-On
Orange Illumination
White Left Front Speaker +
White/Black Left Front Speaker -
Gray Right Front Speaker +
Gray/Black Right Front Speaker -
Green Left Rear Speaker +
Green/Black Left Rear Speaker -
Violet Right Rear Speaker +
Violet/Black Right Rear Speaker -

The Crutchfield Car Selector: Please visit the Crutchfield Car Selector for your specific type of vehicle.

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Customer Q&A

2 questions already asked

What pin type is this - 24 or 14?
[ Adeyeye  Aug 22, 2014 ]
2 answers
I don't think the pin type makes a difference. The connectors supplied with the receiver will mate with the auto mobile and existing receiver connector interfaces. That's why Crutchfield will want the details of how you plan to use the receiver.
[ THOMAS  Aug 25, 2014 ]
i really dont know....i ordered the part and had it professionally installed so to be honest, I didn't pay attention. I'm sorry. Hopefully you can find the answer. Call Metra maybe? Dan
[ DANIEL  Aug 22, 2014 ]
What gauge is this wire?
[ Cody G  Feb 28, 2014 ]
5 answers
16 or 18 gauge. It's the same size as most house stereo speaker wires.
[ JOSH  Mar 01, 2014 ]
I don't have it in front of me currently, but like most harnesses, I would say 18awg would be pretty approximate. I hope this helps.
[ ANDREW  Mar 01, 2014 ]
It was 18 gauge
[ MICHAEL J  Feb 28, 2014 ]
appears to be 20 AWG, but that is just an educated guess.
[ DALE  Feb 28, 2014 ]
It's been installed already do I cannot say for guess is that it about 18 or 22 gauge....standard issue.
[ PAUL  Feb 28, 2014 ]

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